Heart valve sealing devices and delivery devices therefor

ABSTRACT

An implantable prosthetic device includes a coaption portion, paddles, and clasps. The paddles having an outer portion and inner portion. The paddles are extendable from a folded closed position to an open position. A clasp is attached to each of the paddles. The clasps have a fixed arm attached to the inner portion of the paddle and a hoop-shaped moveable arm having a barbed portion. A hinge portion connects the fixed arm to the moveable arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims any benefit of U.S.Provisional Application Ser. No. 62/486,835, filed on Apr. 18, 2017,titled HEART VALVE SEALING DEVICES AND DELIVERY DEVICES THEREFORE, thedisclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates generally to prosthetic devices andrelated methods for helping to seal native heart valves and prevent orreduce regurgitation therethrough, as well as devices and relatedmethods for implanting such prosthetic devices.

BACKGROUND OF THE INVENTION

The native heart valves (i.e., the aortic, pulmonary, tricuspid, andmitral valves) serve critical functions in assuring the forward flow ofan adequate supply of blood through the cardiovascular system. Theseheart valves can be damaged, and thus rendered less effective, bycongenital malformations, inflammatory processes, infectious conditions,or disease. Such damage to the valves can result in seriouscardiovascular compromise or death. For many years the definitivetreatment for such damaged valves was surgical repair or replacement ofthe valve during open heart surgery. However, open heart surgeries arehighly invasive and are prone to many complications. Therefore, elderlyand frail patients with defective heart valves often went untreated.More recently, transvascular techniques have been developed forintroducing and implanting prosthetic devices in a manner that is muchless invasive than open heart surgery. One particular transvasculartechnique that is used for accessing the native mitral and aortic valvesis the trans-septal technique. The trans septal technique comprisesinserting a catheter into the right femoral vein, up the inferior venacava and into the right atrium. The septum is then punctured and thecatheter passed into the left atrium.

A healthy heart has a generally conical shape that tapers to a lowerapex. The heart is four-chambered and comprises the left atrium, rightatrium, left ventricle, and right ventricle. The left and right sides ofthe heart are separated by a wall generally referred to as the septum.The native mitral valve of the human heart connects the left atrium tothe left ventricle. The mitral valve has a very different anatomy thanother native heart valves. The mitral valve includes an annulus portion,which is an annular portion of the native valve tissue surrounding themitral valve orifice, and a pair of cusps, or leaflets, extendingdownward from the annulus into the left ventricle. The mitral valveannulus can form a “D”-shaped, oval, or otherwise out-of-roundcross-sectional shape having major and minor axes. The anterior leafletcan be larger than the posterior leaflet, forming a generally “C”-shapedboundary between the abutting free edges of the leaflets when they areclosed together.

When operating properly, the anterior leaflet and the posterior leafletfunction together as a one-way valve to allow blood to flow only fromthe left atrium to the left ventricle. The left atrium receivesoxygenated blood from the pulmonary veins. When the muscles of the leftatrium contract and the left ventricle dilates (also referred to as“ventricular diastole” or “diastole”), the oxygenated blood that iscollected in the left atrium flows into the left ventricle. When themuscles of the left atrium relax and the muscles of the left ventriclecontract (also referred to as “ventricular systole” or “systole”), theincreased blood pressure in the left ventricle urges the two leafletstogether, thereby closing the one-way mitral valve so that blood cannotflow back to the left atrium and is instead expelled out of the leftventricle through the aortic valve. To prevent the two leaflets fromprolapsing under pressure and folding back through the mitral annulustoward the left atrium, a plurality of fibrous cords called chordaetendineae tether the leaflets to papillary muscles in the leftventricle.

Mitral regurgitation occurs when the native mitral valve fails to closeproperly and blood flows into the left atrium from the left ventricleduring the systolic phase of heart contraction. Mitral regurgitation isthe most common form of valvular heart disease. Mitral regurgitation hasdifferent causes, such as leaflet prolapse, dysfunctional papillarymuscles and/or stretching of the mitral valve annulus resulting fromdilation of the left ventricle. Mitral regurgitation at a centralportion of the leaflets can be referred to as central jet mitralregurgitation and mitral regurgitation nearer to one commissure (i.e.,location where the leaflets meet) of the leaflets can be referred to aseccentric jet mitral regurgitation. Central jet regurgitation occurswhen the edges of the leaflets do not meet in the middle and thus thevalve does not close and regurgitation is present.

Some prior techniques for treating mitral regurgitation in patientsinclude surgically stitching the edges of the native mitral valveleaflets directly to one another. A catheter delivered clip has beenused to attempt to clip the edges of the leaflets together, similar tothe surgical stitching method. However, this clip has shortcomings,since it can only be used to clip the middle edges of the leaflets wherethey overlap by about 2 mm or more. Alternately, attempts have been madeto use multiple clips on the commissures of the mitral valve, wherethere may be more overlap of the leaflets. This technique results in alonger operation time and also joins the patient's leaflets at thesides, restricting blood flow. Additionally, both the surgical and cliptreatments are thought to create stress on patient leaflets.

Despite these prior techniques, there is a continuing need for improveddevices and methods for treating mitral valve regurgitation.

SUMMARY

An implantable prosthetic device includes a coaption portion, paddles,and clasps. The paddles having an outer portion and inner portion. Thepaddles are extendable from a folded closed position to an openposition. A clasp is attached to each of the paddles. The clasps have afixed arm attached to the inner portion of the paddle and a hoop-shapedmoveable arm having a barbed portion. A hinge portion connects the fixedarm to the moveable arm.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention willbecome better understood with regard to the following description andaccompanying drawings in which:

FIGS. 1-6 show an implantable prosthetic device according to a firstembodiment, in various stages of deployment;

FIGS. 7-12 show the implantable prosthetic device of FIGS. 1-6 beingdelivered and implanted within the native mitral valve;

FIGS. 13-13A show another implantable prosthetic device according to asecond embodiment;

FIGS. 14-25 show another implantable prosthetic device according to athird embodiment being delivered and implanted within the native mitralvalve;

FIG. 23A shows a portion of mitral valve tissue captured by a barbedclasp;

FIG. 26 shows a barbed clasp for an implantable prosthetic deviceaccording to one embodiment;

FIG. 27 shows a barbed clasp for an implantable prosthetic deviceaccording to a second embodiment;

FIG. 28 shows a barbed clasp for an implantable prosthetic deviceaccording to a third embodiment;

FIGS. 29-31 show a side view of a barbed clasp for an implantableprosthetic device in various stages of bending;

FIG. 32 shows a barbed clasp for an implantable prosthetic deviceaccording to a fourth embodiment;

FIG. 33 shows a barbed clasp for an implantable prosthetic deviceaccording to a fifth embodiment;

FIG. 34 shows a barbed clasp for an implantable prosthetic deviceaccording to a sixth embodiment;

FIG. 35 shows a barbed clasp for an implantable prosthetic deviceaccording to a seventh embodiment;

FIG. 36 shows a barbed clasp for an implantable prosthetic deviceaccording to an eighth embodiment;

FIGS. 37-52 show a barbed clasp for an implantable prosthetic deviceaccording to a ninth embodiment;

FIGS. 53-55 show a barbed clasp for an implantable prosthetic deviceaccording to a tenth embodiment;

FIG. 56 shows a barbed clasp for an implantable prosthetic deviceaccording to an eleventh embodiment;

FIGS. 56A-56B show alternate embodiments of hinge portions of the barbedclasp of FIG. 56;

FIGS. 57-58 show a barbed clasp for an implantable prosthetic deviceaccording to a twelfth embodiment;

FIG. 57A shows a flat cutout used to make the barbed clasp shown inFIGS. 57 and 58;

FIGS. 59-63 show a barbed clasp for an implantable prosthetic deviceaccording to a thirteenth embodiment;

FIGS. 64-68 show a barbed clasp for an implantable prosthetic deviceaccording to a fourteenth embodiment;

FIGS. 69-73B show exemplary arrangements for securing actuating lines toan exemplary barbed clasp for an implantable prosthetic;

FIGS. 74A-74B show an exemplary barbed clasp being opened with actuatinglines;

FIG. 75 shows an exemplary barbed clasp of the ninth or tenthembodiments with actuating lines;

FIG. 76 shows a barbed clasp for an implantable prosthetic deviceaccording to a fifteenth embodiment;

FIG. 77 shows a barbed clasp for an implantable prosthetic deviceaccording to a sixteenth embodiment;

FIGS. 78-79 shows a barbed clasp for an implantable device according toa seventeenth embodiment;

FIG. 80A-80E shows a barbed clasp for an implantable device according toan eighteenth embodiment;

FIG. 81A-81C shows a barbed clasp for an implantable device according toa nineteenth embodiment;

FIG. 82 shows an exemplary actuation mechanism for use with implantabledevices described herein.

DETAILED DESCRIPTION

As described herein, when one or more components are described as beingconnected, joined, affixed, coupled, attached, or otherwiseinterconnected, such interconnection may be direct as between thecomponents or may be indirect such as through the use of one or moreintermediary components. Also as described herein, reference to a“member,” “component,” or “portion” shall not be limited to a singlestructural member, component, or element but can include an assembly ofcomponents, members, or elements. Also as described herein, the terms“substantially” and “about” are defined as at least close to (andincludes) a given value or state (preferably within 10% of, morepreferably within 1% of, and most preferably within 0.1% of).

A prosthetic device has a coaptation means or coaption element and atleast one anchoring means or anchor. The coaption element is configuredto be positioned within the native heart valve orifice to help form amore effective seal between the native leaflets, thereby reducing orpreventing regurgitation. The coaption element can have a structure thatis impervious to blood and that allows the native leaflets to closetogether on each side of the coaption element during ventricular systoleto block blood from flowing from the left or right ventricle back intothe left or right atrium, respectively. The prosthetic device can beconfigured to seal against two or three native valve leaflets; that is,the device may be used in the native mitral (bicuspid) and tricuspidvalves. The coaption element is sometimes referred to herein as a spacerbecause the coaption element can fill a space between improperlyfunctioning native mitral or tricuspid leaflets that do not closecompletely.

The coaption element can have various shapes. In some embodiments, thecoaption element can have an elongated cylindrical shape having a roundcross-sectional shape. In other embodiments, the coaption element canhave an oval cross-sectional shape, a crescent cross-sectional shape, orvarious other non-cylindrical shapes. The coaption element can have anatrial or upper end positioned in or adjacent to the left atrium, aventricular or lower end positioned in or adjacent to the leftventricle, and a side surface that extends between the native mitralleaflets. In embodiments configured for use in the tricuspid valve, theatrial or upper end is positioned in or adjacent to the right atrium,and the ventricular or lower end is positioned in or adjacent to theright ventricle, and the side surface that extends between the nativetricuspid leaflets.

The anchor can be configured to secure the device to one or both of thenative mitral leaflets such that the coaption element is positionedbetween the two native leaflets. In embodiments configured for use inthe tricuspid valve, the anchor is configured to secure the device toone, two, or three of the tricuspid leaflets such that the coaptionelement is positioned between the three native leaflets. In someembodiments, the anchor can attach to the coaption element at a locationadjacent the ventricular end of the coaption element. In someembodiments, the anchor can attach to an actuation means such as a shaftor actuation wire, to which the coaption element is also attached. Insome embodiments, the anchor and the coaption element can be positionedindependently with respect to each other by separately moving each ofthe anchor and the coaption element along the longitudinal axis of theshaft or actuation wire. In some embodiments, the anchor and thecoaption element can be positioned simultaneously by moving the anchorand the coaption element together along the longitudinal axis of theshaft or actuation wire. The anchor can be configured to be positionedbehind a native leaflet when implanted such that the leaflet is capturedby the anchor.

The prosthetic device can be configured to be implanted via a deliverymeans such as a delivery sheath. The coaption element and the anchor canbe compressible to a radially compressed state and can beself-expandable to a radially expanded state when compressive pressureis released. The device can be configured for the anchor to be expandedradially away from the still-compressed coaption element initially inorder to create a gap between the coaption element and the anchor. Anative leaflet can then be positioned in the gap. The coaption elementcan be expanded radially, closing the gap between the coaption elementand the anchor and capturing the leaflet between the coaption elementand the anchor. In some embodiments, the anchor and coaption element areoptionally configured to self-expand. The implantation methods forvarious embodiments can be different, and are more fully discussed belowwith respect to each embodiment. Additional information regarding theseand other delivery methods can be found in U.S. Pat. No. 8,449,599 andU.S. Patent Application Publication Nos. 2014/0222136, and 2014/0067052,2016/0331523 each of which is incorporated herein by reference in itsentirety.

The disclosed prosthetic devices are prevented from atrial embolizationby having the anchor hooked to a leaflet, taking advantage of thetension from native chordae tendineae to resist high systolic pressureurging the device toward the left atrium. During diastole, the devicescan rely on the compressive and retention forces exerted on the leafletthat is captured by the anchor to resist embolization into the leftventricle.

Referring now to FIGS. 1-6, an implantable prosthetic device 100 isshown in various stages of deployment. The device 100 is deployed from adelivery sheath 102 and includes a coaption portion 104 and an anchorportion 106. The coaption portion 104 of the device 100 includes acoaption element 110 that is adapted to be implanted between theleaflets of the native mitral valve and is slideably attached to anactuation wire or shaft 112. The anchor portion 106 is actuatablebetween open and closed conditions and can take a wide variety of forms,such as, for example, paddles, gripping elements, or the like. Actuationof the actuation wire 112 opens and closes the anchor portion 106 of thedevice 100 to capture the mitral valve leaflets during implantation. Theactuation wire or shaft 112 may take a wide variety of different forms.For example, the actuation wire or shaft may be threaded such thatrotation of the actuation wire or shaft moves the anchor portion 106relative to the coaption portion 104. Or, the actuation wire or shaftmay be unthreaded, such that pushing or pulling the actuation wire orshaft 112 moves the anchor portion 106 relative to the coaption portion104.

The anchor portion 106 of the device 100 includes outer paddles orgripping elements 120 and inner paddles or gripping elements 122 thatare connected between a cap 114 and the coaption element 110 by portions124, 126, 128. The portions 124, 126, 128 may be hinged and/or flexibleto move between all of the positions described below. The actuation wire112 extends through the delivery sheath and the coaption element 110 tothe cap 114 at the distal end of the anchor portion 106. Extending andretracting the actuation wire 112 increases and decreases the spacingbetween the coaption element 110 and the cap 114, respectively. Anattaching means or collar (not shown) removably attaches the coaptionelement 110 to the delivery sheath 102 so that the coaption element 110slides along the actuation wire 112 during actuation to open and closethe paddles 120, 122 of the anchor portion 106.

Referring to FIG. 3, the barbed clasps 130 include a base or fixed arm132, a moveable arm 134, barbs 136, and a hinge portion 138. The fixedarms 132 are attached to the inner paddles 122, with the hinge portion138 disposed proximate the coaption element 110. The hinge portion 138provides a spring force between the fixed and moveable arms 132, 134 ofthe barbed clasp 130. The hinge portion 138 can be any suitable hinge,such as a flexible hinge, a spring hinge, a pivot hinge, or the like. Incertain embodiments, the hinge portion 138 is a flexible piece ofmaterial integrally formed with the fixed and moveable arms 132, 134.The fixed arms 132 are attached to the inner paddles 122 and remainstationary relative to the inner paddles 122 when the moveable arms 134are opened to open the barbed clasps 130 and expose the barbs 136. Thebarbed clasps 130 are opened by applying tension to actuation lines 116attached to the ends of the moveable arms 134, thereby causing themoveable arms 134 to pivot on the hinge portions 138.

During implantation, the paddles 120, 122 are opened and closed tocapture the native mitral valve leaflets between the paddles 120, 122and the coaption element 110. The barbed clasps 130 further secure thenative leaflets by engaging the leaflets with barbs 136 and pinching theleaflets between the moveable and fixed arms 134, 132. The barbs 136 ofthe barbed clasps 130 increase friction with the leaflets or maypartially or completely puncture the leaflets. The actuation lines 116can be actuated independently so that each barbed clasp 130 can beopened and closed independently. Independent operation allows oneleaflet to be captured at a time, or for the repositioning of a clasp130 on a leaflet that was insufficiently captured, without altering asuccessful grasp on the other leaflet. The barbed clasps 130 not onlyopen and close independent from each other but can fully be opened andclosed independent from the position of the inner paddle 122, therebyallowing leaflets to be captured in a variety of positions as theparticular situation requires.

The barbed clasps 130 can be opened independently by pulling on anattached actuating means or actuation line 116 that extends through thedelivery sheath 102 to the end of the barbed clasp 130. The actuationline 116 can take a wide variety of forms, such as, for example, a line,a suture, a wire, a rod, a catheter, or the like. The barbed clasps 130can be spring loaded so that in the closed position the barbed clasps130 continue to provide a pinching force on the captured native leaflet.This pinching force remains constant regardless of the position of theinner paddles 122. Barbs 136 of the barbed clasps 130 can pierce thenative leaflets to further secure the native leaflets.

Referring now to FIG. 1, the device 100 is shown in an elongated orfully open condition for deployment from the delivery sheath. The device100 is loaded in the delivery sheath in the fully open position, becausethe fully open position takes up the least space and allows the smallestcatheter to be used (or the largest device 100 to be used for a givencatheter size). In the elongated condition the cap 114 is spaced apartfrom the coaption element 110 such that the paddles 120, 122 of theanchor portion 106 are inverted or fully open. In some embodiments, anangle formed between the interior of the outer and inner paddles 120,122 is approximately 180 degrees. The barbed clasps 130 are kept in aclosed condition during deployment through the delivery sheath 102 sothat the barbs 136 (FIG. 3) do not catch or damage the sheath or tissuein the patient's heart.

Referring now to FIG. 1A, the device 100 is shown in an elongateddetangling condition, similar to FIG. 1, but with the barbed clasps 130in a fully open position, ranging from about 140 degrees to about 200degrees, to about 170 degrees to about 190 degrees, or about 180 degreesbetween fixed and moveable portions of the barbed clasps 130. Fullyopening the device 100 and the clasps 130 has been found to improve easeof detanglement from anatomy of the patient during implantation of thedevice 100.

Referring now to FIG. 2, the device 100 is shown in a shortened or fullyclosed condition. The compact size of the device 100 in the shortenedcondition allows for easier maneuvering and placement within the heart.To move the device 100 from the elongated condition to the shortenedcondition, the actuation wire 112 is retracted to pull the cap 114towards the coaption element 110. The hinges or flexible connections 126between the outer paddle 120 and inner paddle 122 are limited inmovement such that compression forces acting on the outer paddle 120from the cap 114 being retracted towards the coaption element 110 causethe paddles or gripping elements 120, 122 to move radially outward.During movement from the open to closed position, the outer paddles 120maintain an acute angle with the actuation wire 112. The outer paddles120 can optionally be biased toward a closed position. The inner paddles122 during the same motion move through a considerably larger angle asthey are oriented away from the coaption element 110 in the opencondition and collapse along the sides of the coaption element 110 inthe closed condition. In certain embodiments, the inner paddles 122 arethinner and/or narrower than the outer paddles 120, and the hinge orflexible portions 126, 128 connected to the inner paddles 122 arethinner and/or more flexible to allow more movement than the hinge orflexible portion 124 connecting the outer paddle 124 to the cap 114.

Referring now to FIGS. 3-5, the device 100 is shown in a partially open,capture-ready condition. To transition from the fully closed to thepartially open condition, the actuation wire 112 is extended to push thecap 114 away from the coaption element 110, thereby pulling on the outerpaddles 120, which in turn pulls on the inner paddles 122, causing theanchor portion 106 to partially unfold. The actuation lines 116 are alsoretracted to open the clasps 130 so that the leaflets can be captured.

Referring now to FIG. 4, one of the actuation lines 116 is extended toallow one of the clasps 130 to close. Referring now to FIG. 5, the otheractuation line 116 is extended to allow the other clasp 130 to close.Either or both of the actuation lines 116 may be repeatedly actuated torepeatedly open and close the barbed clasps 130.

Referring now to FIG. 6, the device 100 is shown in a fully closed anddeployed condition. The delivery sheath 102 and actuation wire 112 areretracted and the paddles 120, 122 and clasps 130 remain in a fullyclosed position. Once deployed, the device 100 may be maintained in thefully closed position with a mechanical latch or may be biased to remainclosed through the use of spring materials, such as steel, other metals,plastics, composites, etc. or shape-memory alloys such as Nitinol. Forexample, the hinged or flexible portions 124, 126, 128, 138, and/or theinner and outer paddles 122, and/or an additional biasing component (seecomponent 224 in FIG. 13) may be formed of metals such as steel orshape-memory alloy, such as Nitinol—produced in a wire, sheet, tubing,or laser sintered powder—and are biased to hold the outer paddles 120closed around the coaption element 110 and the barbed clasps 130 pinchedaround native leaflets. Similarly, the fixed and moveable arms 132, 134of the barbed clasps 130 are biased to pinch the leaflets. In certainembodiments, the hinge portions 124, 126, 128, 138, and/or the inner andouter paddles 122, and/or an additional biasing component (see component224 in FIG. 13) may be formed of any other suitably elastic material,such as a metal or polymer material, to maintain the device in theclosed condition after implantation.

Referring now to FIGS. 7-12, the implantable device 100 of FIGS. 1-6 isshown being delivered and implanted within a native mitral valve 40 of aheart 10. Referring now to FIG. 7, the delivery sheath is inserted intothe left atrium 20 through the septum and the device 100 is deployedfrom the delivery sheath in the fully open condition. The actuation wire112 is then retracted to move the device 100 into the fully closedcondition shown in FIG. 8. As can be seen in FIG. 9, the device 100 ismoved into position within the mitral valve 40 into the ventricle 30 andpartially opened so that the leaflets 42, 44 can be captured. Referringnow to FIG. 10, an actuation line 116 is extended to close one of theclasps 130, capturing a leaflet 42. FIG. 11 shows the other actuationline 116 being then extended to close the other clasp 130, capturing theremaining leaflet 44. Lastly, as can be seen in FIG. 12, the deliverysheath 102 and actuation wire 112 are then retracted and the device 100is fully closed and deployed in the native mitral valve 400.

Referring now to FIG. 13, an implantable prosthetic device 200 is shown.The implantable device 200 is one of the many different configurationsthat the device 100 that is schematically illustrated in FIGS. 1-12 cantake. The device 200 is deployed from a delivery sheath (not shown) andincludes a coaption portion 204 and an anchor portion 206. The device200 is loaded in the delivery sheath in the fully open position, becausethe fully open position takes up the least space and allows the smallestcatheter to be used (or the largest device 200 to be used for a givencatheter size). The coaption portion 204 of the device includes acoaption element 210 for implantation between the leaflets of the nativemitral valve that is slideably attached to an actuation wire or shaft212. Actuation of the actuation wire 212 opens and closes the anchorportion 206 of the device 200 to capture the mitral valve leafletsduring implantation.

The anchor portion 206 of the device 200 includes outer paddles 220 andinner paddles 222 that are hingeably connected to the cap 214 and thecoaption element 210. The actuation wire 212 extends through thedelivery sheath (not shown), a collar 211, and the coaption element 210to the cap 214 at the distal end of the anchor portion 206. Extendingand retracting the actuation wire 212 increases and decreases thespacing between the coaption element 210 and the cap 214, respectively.The collar 211 optionally includes a collar seal 213 that forms a sealaround the actuation wire or shaft 212 during implantation of the device200, and that seals shut when the actuation wire 212 is removed tosubstantially close the device 200 to blood flow through the interior ofthe coaption element 210 after implantation. In some embodiments, thecollar 2011 removably engages and attaches the coaption element 200 tothe delivery sheath so that the coaption element 210 slides along theactuation wire 212 during actuation to open and close the paddles 220,222 of the anchor portion 206. In some embodiments, the collar 2011 isheld closed around the coaption element 2010 by the actuation wire 212,such that removal of the actuation wire 212 allows fingers (not shown)of the collar to open, releasing the coaption element 210. In someembodiments, the cap 2014 optionally includes a seal 216 and/or aninsert 218 that fit inside an opening 215 of the coaption element 210,the coaption element 210 having a hollow interior. The seal 216 and/orinsert 218 maintain the coaption element 210 substantially closed toblood flow when the actuation wire 212 is withdrawn and the device 200is implanted.

The coaption element 210 and paddles 220, 222 are formed from a coveringthat may be a mesh, woven, braided, or formed in any other suitable way.The covering may be cloth, shape-memory alloy wire—such as Nitinol—toprovide shape setting capability, or any other flexible materialsuitable for implantation in the human body. Paddle frames 224 provideadditional pinching force between the outer paddles 222 and the coaptionelement 210, and assist in wrapping the leaflets around the sides of thecoaption element 210 for a better seal between the coaption element 210and the leaflets. In some embodiments, the covering extends around thepaddle frames 224.

The barbed clasps 230 include a base or fixed arm 232, a moveable arm234, barbs 236, and a hinge portion 238. The fixed arms 232 are attachedto the inner paddles 222, with the hinge portion 238 disposed proximatethe coaption element 210. The fixed arms 232 are attached to the innerpaddles 222 through holes or slots 233 with sutures (not shown). Thefixed arms 232 may be attached to the inner paddles 222 with anysuitable means, such as screws or other fasteners, crimped sleeves,mechanical latches or snaps, welding, adhesive, or the like. The fixedarms 232 remain stationary relative to the inner paddles 222 when themoveable arms 234 are opened to open the barbed clasps 230 and exposethe barbs 236. The barbed clasps 230 are opened by applying tension toactuation lines (not shown) attached to holes 235 disposed at ends ofthe moveable arms 234, thereby causing the moveable arms 234 to pivot onthe hinge portions 238.

During implantation, the paddles 220, 222 are opened and closed tocapture the native mitral valve leaflets between the paddles 220, 222and the coaption element 210. The barbed clasps 230 further secure thenative leaflets by engaging the leaflets with barbs 236 and pinching theleaflets between the moveable and fixed arms 234, 232. The barbs 236 ofthe barbed clasps 230 increase friction with the leaflets or maypartially or completely puncture the leaflets. The actuation lines canbe actuated independently so that each barbed clasp 230 can be openedand closed independently. Independent operation allows one leaflet to becaptured at a time, or for the repositioning of a clasp 230 on a leafletthat was insufficiently captured, without altering a successful grasp onthe other leaflet. The barbed clasps 230 not only open and closeindependent from each other but can be fully opened and closedindependent from the position of the inner paddle 222, thereby allowingleaflets to be captured in a variety of positions as the particularsituation requires.

Referring now to FIGS. 14-25, an implantable device 300 is shown beingdelivered and implanted within the native mitral valve 40 of the heart10. The device 300 is similar to implantable device 200 of FIG. 13,though device 300 has a covering over the coaption element 310, clasps330, inner paddles 322 and/or the outer paddles 320. The device 300 isdeployed from a delivery sheath 302 and includes a coaption portion 304and an anchor portion 306. The coaption portion 304 of the deviceincludes a coaption element 310 for implantation between the leaflets ofthe native mitral valve that is slideably attached to an actuation wireor shaft 312. Actuation of the actuation wire or shaft 312 opens andcloses the anchor portion 306 of the device 300 to capture the mitralvalve leaflets during implantation.

The anchor portion 306 of the device 300 includes outer paddles 320 andinner paddles 322 that are flexibly connected to the cap 314 and thecoaption element 310. The actuation wire 312 extends through a collar303 (see FIG. 20), delivery sheath 302, and the coaption element 310 tothe cap 314 at the distal end of the anchor portion 306. Extending andretracting the actuation wire 312 increases and decreases the spacingbetween the coaption element 310 and the cap 314, respectively. Fingersof the collar 303 removably attach the coaption element 310 to thedelivery sheath 302 so that the coaption element 310 slides along theactuation wire 312 during actuation to open and close the paddles 320,322 of the anchor portion 306. In some embodiments, the collar 303 isheld closed around the coaption element 310 by the actuation wire 312,such that removal of the actuation wire 312 allows the fingers of thecollar 303 to open, releasing the coaption element 310.

The coaption element 310 and paddles 320, 322 are formed from a flexiblematerial that may be a mesh, woven, braided, or formed in any othersuitable way. The flexible material may be cloth, shape-memory alloywire—such as Nitinol—to provide shape setting capability, or any otherflexible material suitable for implantation in the human body.

The barbed clasps 330 include a base or fixed arm 332, a moveable arm334, barbs 336 (see FIG. 20), and a hinge portion 338. The fixed arms332 are attached to the inner paddles 322, with the hinge portion 338disposed proximate the coaption element 310. Sutures (not shown) attachthe fixed arms 332 to the inner paddles 322. The fixed arms 332 may beattached to the inner paddles 322 with any suitable means, such asscrews or other fasteners, crimped sleeves, mechanical latches or snaps,welding, adhesive, or the like. The fixed arms 332 remain stationarywhen the moveable arms 334 are opened to open the barbed clasps 330 andexpose the barbs 336. The barbed clasps 330 are opened by applyingtension to actuation lines 316 attached to the ends of the moveable arms334, thereby causing the moveable arms 334 to pivot on the hingeportions 338.

During implantation, the paddles 320, 322 are opened and closed tocapture the native mitral valve leaflets between the paddles 320, 322and the coaption element 310. The outer paddles 320 have a wide curvedshape that fits around the curved shape of the coaption element 310 tomore securely grip the leaflets. The curved shape and rounded edges ofthe outer paddle 320 also prohibits tearing of the leaflet tissue. Thebarbed clasps 330 further secure the native leaflets by engaging theleaflets with barbs 336 and pinching the leaflets between the moveableand fixed arms 334, 332. The barbs 336 of the barbed clasps 330 increasefriction with the leaflets or may partially or completely puncture theleaflets. The actuation lines can be actuated independently so that eachbarbed clasp 330 can be opened and closed independently. Independentoperation allows one leaflet to be captured at a time, or for therepositioning of a clasp 330 on a leaflet that was insufficientlycaptured, without altering a successful grasp on the other leaflet. Thebarbed clasps 330 not only open and close independent from each otherbut can be fully opened and closed independent from the position of theinner paddle 322, thereby allowing leaflets to be captured in a varietyof positions as the particular situation requires.

The device 300 is loaded in the delivery sheath in the fully openposition, because the fully open position takes up the least space andallows the smallest catheter to be used (or the largest device 300 to beused for a given catheter size). Referring now to FIG. 14, the deliverysheath is inserted into the left atrium 20 through the septum and thedevice 300 is deployed from the delivery sheath 302 in the fully opencondition. The actuation wire 312 is then retracted to move the device300 into the fully closed condition shown in FIGS. 15-16 and thenmaneuvered towards the mitral valve 40 as shown in FIG. 17. Referringnow to FIG. 18, when the device 300 is aligned with the mitral valve 40,the actuation wire 312 is extended to open the paddles 320, 322 into thepartially opened position and the actuation lines 316 are retracted toopen the barbed clasps 330 to prepare for leaflet capture. Next, asshown in FIGS. 19-20, the partially open device 300 is inserted throughthe mitral valve 40 until leaflets are properly positioned in betweenthe inner paddles 322 and the coaption element 310 and inside the openbarbed clasps 330. FIG. 21 shows the device 300 with both clasps 330closed, though the barbs 336 of one clasp 330 missed one of the leaflets44. As can be seen in FIGS. 22-23, the out of position clasp 330 isopened and closed again to properly capture the missed leaflet 44. Whenboth leaflets 42, 44 are captured properly, the actuation wire 312 isretracted to move the device 300 into the fully closed position shown inFIG. 24. With the device 300 fully implanted in the native mitral valve40, the actuation wire 312 is withdrawn to release the collar 303 froman upper end or plate 311 of the coaption element 310. Once deployed,the device 300 may be maintained in the fully closed position with amechanical means such as a latch or may be biased to remain closedthrough the use of spring material, such as steel, and/or shape-memoryalloys such as Nitinol. For example, the paddles 320, 322 may be formedof steel or Nitinol shape-memory alloy—produced in a wire, sheet,tubing, or laser sintered powder—and are biased to hold the outerpaddles 320 closed around the coaption element 310 and the barbed clasps330 pinched around native leaflets.

Referring now to FIG. 23A, a close-up view of one of the leaflets 42, 44captured by one of the clasps 330 is shown. The leaflet 42, 44 iscaptured between the moveable and fixed arms 334, 332 of the clasp 330.As shown in FIG. 23A, the tissue of the leaflet 42, 44 is not pierced bythe barbs 336, though in some embodiments the barbs 336 may partially orfully pierce through the leaflet 42, 44. The angle and height of thebarbs 336 relative to the moveable arm 334 helps to secure the leaflet42, 44 within the clasp 330. In particular, a force pulling the implantoff of the native leaflet will encourage the barbs 336 to further engagethe tissue, thereby ensuring better retention. Retention of the leaflet42, 44 in the clasp 330 is further improved by the position of fixed arm332 near the barbs 336 when the clasp 330 is closed. In thisarrangement, the tissue is formed by the fixed and moveable arms 332,334 and the barbs 336 into an S-shaped torturous path. Thus, forcespulling the leaflet away from the clasp 330 will encourage the tissue tofurther engage the barbs 336 before the leaflets can escape

Referring now to FIG. 26, an exemplary barbed clasp 400 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 400 is formed from a top layer 402 anda bottom layer 404. The two-layer design of the clasp 400 allow thinnersheets of material to be used, thereby improving the flexibility of theclasp 400 over a clasp formed from a single thicker sheet, whilemaintaining the strength of the clasp 400 needed to successfully retaina native valve leaflet.

The barbed clasp 400 includes a fixed arm 410, a hinged portion 420, anda movable arm 430 having a barbed portion 440. The top and bottom layers402, 404 have a similar shape and in certain embodiments are attached toeach other at the barbed end 440. The hinged portion 420 isspring-loaded so that the fixed and moveable arms 410, 430 are biasedtoward each other when the barbed clasp 400 is in a closed condition.When assembled to an implantable prosthetic device, the fixed arm 410 isattached to a portion of the prosthetic device. The clasp 400 is openedby pulling on an actuation line attached to the moveable arm 430 untilthe spring force of the hinge portion 420 is overcome.

The fixed arm 410 is formed from a tongue 411 of material extending fromthe hinged portion 420 between two side beams 431 of the moveable arm430. The tongue 411 is biased between the side beams 431 by the hingeportion 420 such that force must be applied to move the tongue 411 froma neutral position located beyond the side beams 431 to a preloadedposition substantially parallel with the side beams 431. The tongue 411is held in the preloaded position by a T-shaped cross-bar 414 that isattached to the tongue 411 and extends outward to engage the side beams431. In certain embodiments, the angle between the fixed and moveablearms 410, 430 when the tongue is in the neutral position is about 30 toabout 100 degrees, 30 to about 90 degrees, or about 30 to about 60degrees, or about 40 to about 50 degrees, or about 45 degrees.

The tongue 411 includes holes 412 for receiving sutures (not shown) thatattach the fixed arm 410 to an implantable device. The fixed arm 410 maybe attached to an implantable device by various attaching means, such asscrews or other fasteners, crimped sleeves, mechanical latches or snaps,welding, adhesive, or the like. In certain embodiments, the holes 412are elongated slots or oval-shaped holes to accommodate sliding of thelayers 402, 404 without damaging the sutures attaching the clasp 400 toan implantable device.

The hinge portion 420 is formed by two beam loops 422 that extend fromthe tongue 411 of the fixed arm 410 to the side beams 431 of themoveable arm 430. In certain embodiments, the beam loops 422 arenarrower than the tongue 411 and side beam 431 to provide additionalflexibility. The beam loops 422 each include a center portion 424extending from the tongue 411 and an outer portion 426 extending to theside beams 431. The beam loops 422 are bent into a somewhat spiral orhelical shape by bending the center and outer portions 424, 426 inopposite directions, thereby forming an offset or step distance 428between the tongue 411 and side beams 431. The step distance 428provides space between the arms 410, 430 to accommodate the nativeleaflet of the mitral valve after it is captured. In certainembodiments, the step distance 428 is about 0.5 millimeter to about 1millimeters, or about 0.75 millimeters.

When viewed in a top plan view, the beam loops have an “omega-like”shape. This shape of the beam loops 422 allows the fixed and moveablearms 410, 430 to move considerably relative to each other withoutplastically deforming the clasp material. For example, in certainembodiments, the tongue 411 can be pivoted from a neutral position thatis approximately 45 degrees beyond the moveable arm 430 to a fully openposition that ranges from about 140 degrees to about 200 degrees, toabout 170 degrees to about 190 degrees, or about 180 degrees from themoveable arm 430 without plastically deforming the clasp material. Incertain embodiments, the clasp material plastically deforms duringopening without reducing or without substantially reducing the pinchforce exerted between the fixed and moveable arms in the closedposition.

Preloading the tongue 411 enables the clasp 400 to maintain a pinchingor clipping force on the native leaflet when closed while also beingable to be opened wide to more easily capture the native leaflet. Thepreloading of the tongue 411 provides a significant advantage over priorart clips that provide little or no pinching force when closed.Additionally, closing the clasp 400 with spring force is a significantimprovement over clips that use a one-time locking closure mechanism, asthe clasp 400 can be repeatedly opened and closed for repositioning onthe leaflet while still maintaining sufficient pinching force whenclosed.

The barbed portion 440 of the moveable arm 430 includes an eyelet 442,barbs 444, and barb supports 446. Positioning the barbed portion of theclasp 400 at an end of the moveable arm 430 increases the space betweenthe barbs 444 and the fixed arm 410 when the clasp 400 is opened,thereby improving the ability of the clasp 400 to successfully capture aleaflet during implantation. This distance also allows the barbs 444 tomore reliably disengage from the leaflet for repositioning. In certainembodiments, the barbs of the clasps may be staggered longitudinally tofurther distribute pinch forces and local leaflet stress.

The barbs 444 are laterally spaced apart at the same distance from thehinge portion 420, providing a superior distribution of pinching forceson the leaflet tissue while also making the clasp more robust to leafletcapture than barbs arranged in a longitudinal row. In some embodiments,the barbs 444 can be staggered to further distribute pinch forces andlocal leaflet stress.

The barbs 444 are formed from the bottom layer 404 and the barb supports446 are formed from the top layer. In certain embodiments, the barbs areformed from the top layer 402 and the barb supports are formed from thebottom layer 404. Forming the barbs 444 only in one of the two layers402, 404 allows the barbs to be thinner and therefore effectivelysharper than a barb formed from the same material that is twice asthick. The barb supports 446 extend along a lower portion of the barbs444 to stiffen the barbs 444, further improving penetration andretention of the leaflet tissue. In certain embodiments, the ends of thebarbs 444 are further sharpened using any suitable sharpening means.

The barbs 444 are angled away from the moveable arm 430 such that theyeasily penetrate tissue of the native leaflets with minimal pinching orclipping force. The barbs 444 extend from the moveable arm at an angleof about 45 degrees to about 75 degrees, or about 45 degrees to about 60degrees, or about 48 to about 56 degrees, or about 52 degrees. The angleof the barbs 444 provides further benefits, in that force pulling theimplant off of the native leaflet will encourage the barbs 444 tofurther engage the tissue, thereby ensuring better retention. Retentionof the leaflet in the clasp 400 is further improved by the position ofthe T-shaped cross bar 414 near the barbs 444 when the clasp 400 isclosed. In this arrangement, the tissue pierced by the barbs 444 ispinched against the moveable arm 430 at the cross bar 414 location,thereby forming the tissue into an S-shaped torturous path as it passesover the barbs 444. Thus, forces pulling the leaflet away from the clasp400 will encourage the tissue to further engage the barbs 444 before theleaflets can escape.

Each layer 402, 404 of the clasp 400 is laser cut from a sheet ofshape-memory alloy, such as Nitinol. The top layer 402 is aligned andattached to the bottom layer 404. In certain embodiments, the layers402, 404 are attached at the barbed end 440 of the moveable arm 430. Forexample, the layers 402, 404 may be attached only at the barbed end 440,to allow the remainder of the layers to slide relative to one another.Portions of the combined layers 402, 404, such as a fixed arm 410, barbs444 and barb supports 446, and beam loops 422 are bent into a desiredposition. The layers 402, 404 may be bent and shapeset together or maybe bent and shapeset separately and then joined together. The clasp 400is then subjected to a shape-setting process so that internal forces ofthe material will tend to return to the set shape after being subjectedto deformation by external forces. After shape setting, the tongue 411is moved to its preloaded position so that the cross-bar 414 can beattached. Consequently, the clasp 400 can be completely flattened fordelivery through a delivery sheath and allowed to expand once deployedwithin the heart.

The clasp 400 is opened and closed by applying and releasing tension onan actuation means such as an actuation line, suture, wire, rod,catheter, or the like (not shown) attached to the moveable arm 430. Thesuture is inserted through an eyelet 442 near the barbed portion 440 ofthe moveable arm 430 and wraps around the end of the moveable arm 430before returning to the delivery sheath. In certain embodiments, anintermediate suture loop is made through the eyelet and the suture isinserted through the intermediate loop. An intermediate loop of suturematerial reduces friction experienced by the actuation suture relativeto the friction between the actuation suture and the clasp material.When the suture is looped through the eyelet 442 or intermediate loop,both ends of the actuation suture extend back into and through thedelivery sheath 102 (see FIG. 1). The suture can be removed by pullingone end of the suture proximally until the other end of the suture pullsthrough the eyelet or intermediate loop and back into the deliverysheath.

Referring now to FIG. 27, an exemplary barbed clasp 500 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 500 is substantially the same as thebarbed clasp 400, except the barbed clasp 500 includes a suture pin 543disposed across an opening 542, instead of the hole 442. The barbedclasp 500 is formed from a top layer 502 and a bottom layer 504. Thetwo-layer design of the clasp 500 allow thinner sheets of material to beused, thereby improving the flexibility of the clasp 500 over a claspformed from a single thicker sheet, while maintaining the strength ofthe clasp 500 needed to successfully retain a native valve leaflet.

The barbed clasp 500 includes a fixed arm 510, a hinged portion 520, anda movable arm 530 having a barbed portion 540. The top and bottom layers502, 504 have a similar shape and in certain embodiments are attached toeach other at the barbed end 540. The hinged portion 520 isspring-loaded so that the fixed and moveable arms 510, 530 are biasedtoward each other when in the barbed clasp 500 is in a closed condition.When assembled to an implantable prosthetic device, the fixed arm 510 isattached to a portion of the prosthetic device. The clasp 500 is openedby pulling on an actuation means or actuation line attached to themoveable arm 530 until the spring force of the hinge portion 520 isovercome.

The fixed arm 510 is formed from a tongue 511 of material extending fromthe hinged portion 520 between two side beams 531 of the moveable arm530. The tongue 511 is biased between the side beams 531 by the hingeportion 520 such that force must be applied to move the tongue 511 froma neutral position located beyond the side beams 531 to a preloadedposition substantially parallel with the side beams 531. The tongue 511is held in the preloaded position by a T-shaped cross-bar 514 that isattached to the tongue 511 and extends outward to engage the side beams531. In certain embodiments, the angle between the fixed and moveablearms 510, 530 when the tongue is in the neutral position is about 30 toabout 100 degrees, or about 30 to about 90 degrees, or about 30 to about60 degrees, or about 40 to about 50 degrees, or about 45 degrees.

The tongue 511 includes holes 512 for receiving sutures (not shown) thatattach the fixed arm 510 to an implantable device. The fixed arm 510 maybe attached to an implantable device by various attaching means, such asscrews or other fasteners, crimped sleeves, mechanical latches or snaps,welding, adhesive, or the like. In certain embodiments, the holes 512are elongated slots or oval-shaped holes to accommodate sliding of thelayers 502, 504 without damaging the sutures attaching the clasp 500 toan implantable device.

The hinge portion 520 is formed by two beam loops 522 that extend fromthe tongue 511 of the fixed arm 510 to the side beams 531 of themoveable arm 530. In certain embodiments, the beam loops 522 arenarrower than the tongue 511 and side beam 531 to provide additionalflexibility. The beam loops 522 each include a center portion 524extending from the tongue 511 and an outer portion 526 extending to theside beams 531. The beam loops 522 are bent into a somewhat spiral orhelical shape by bending the center and outer portions 524, 526 inopposite directions, thereby forming a step distance 528 between thetongue 511 and side beams 531. The step distance 528 provides spacebetween the arms 510, 530 to accommodate the native leaflet of themitral valve after it is captured. In certain embodiments, the stepdistance 528 is about 0.5 millimeter to about 1 millimeters, or about0.75 millimeters.

When viewed in a top plan view, the beam loops have an “omega-like”shape. This shape of the beam loops 522 allows the fixed and moveablearms 510, 530 to move considerably relative to each other withoutplastically deforming the clasp material. For example, in certainembodiments, the tongue 511 can be pivoted from a neutral position thatis approximately 45 degrees beyond the moveable arm 530 to a fully openposition that ranges from about 140 degrees to about 200 degrees, toabout 170 degrees to about 190 degrees, or about 180 degrees from themoveable arm 530 without plastically deforming the clasp material. Incertain embodiments, the clasp material plastically deforms duringopening without reducing the pinch force exerted between the fixed andmoveable arms in the closed position.

Preloading the tongue 511 enables the clasp 500 to maintain a pinchingor clipping force on the native leaflet when closed while also beingable to be opened wide to more easily capture the native leaflet. Thepreloading of the tongue 511 provides a significant advantage over priorart clips that provide little or no pinching force when closed.Additionally, closing the clasp 500 with spring force is a significantimprovement over clips that use a one-time locking closure mechanism, asthe clasp 500 can be repeatedly opened and closed for repositioning onthe leaflet while still maintaining sufficient pinching force whenclosed.

The barbed portion 540 of the moveable arm 530 includes an eyelet 542,barbs 544, and barb supports 546. Positioning the barbed portion of theclasp 500 at an end of the moveable arm 530 increases the space betweenthe barbs 544 and the fixed arm 510 when the clasp 500 is opened,thereby improving the ability of the clasp 500 to successfully capture aleaflet during implantation. This distance also allows the barbs 544 tomore reliably disengage from the leaflet for repositioning. In certainembodiments, the barbs of the clasps may be staggered longitudinally tofurther distribute pinch forces and local leaflet stress.

The barbs 544 are laterally spaced apart at the same distance from thehinge portion 520, providing a superior distribution of pinching forceson the leaflet tissue while also making the clasp more robust to leafletcapture than barbs arranged in a longitudinal row.

The barbs 544 are formed from the bottom layer 504 and the barb supports546 are formed from the top layer. Forming the barbs 544 only in one ofthe two layers 502, 504 allows the barbs to be thinner and thereforeeffectively sharper than a barb formed from the same material that istwice as thick. The barb supports 546 extend along a lower portion ofthe barbs 544 to stiffen the barbs 544, further improving penetrationand retention of the leaflet tissue. In certain embodiments, the ends ofthe barbs 544 are further sharpened using any suitable sharpening means.

The barbs 544 are angled away from the moveable arm 530 such that theyeasily penetrate tissue of the native leaflets with minimal pinching orclipping force. The barbs 544 extend from the moveable arm at an angleof about 45 to about 75 degrees, or about 45 to about 60 degrees, orabout 48 to about 56 degrees, or about 52 degrees. The angle of thebarbs 544 provides further benefits, in that force pulling the implantoff of the native leaflet will encourage the barbs 544 to further engagethe tissue, thereby ensuring better retention. Retention of the leafletin the clasp 500 is further improved by the position of the T-shapedcross bar 514 near the barbs 544 when the clasp 500 is closed. In thisarrangement, the tissue pierced by the barbs 544 is pinched against themoveable arm 530 at the cross bar 514 location, thereby forming thetissue into an S-shaped torturous path as it passes over the barbs 544.Thus, forces pulling the leaflet away from the clasp 500 will encouragethe tissue to further engage the barbs 544 before the leaflets canescape.

Each layer 502, 504 of the clasp 500 is laser cut from a sheet ofshape-memory alloy, such as Nitinol. The top layer 502 is aligned andattached to the bottom layer 504. In certain embodiments, the layers502, 504 are attached at the barbed end 540 of the moveable arm 530. Forexample, the layers 402, 404 may be attached only at the barbed end 440,to allow the remainder of the layers to slide relative to one another.Portions of the combined layers 502, 504, such as a fixed arm 510, barbs544 and barb supports 546, and beam loops 522 are bent into a desiredposition. The clasp 500 is then subjected to a shape-setting process sothat internal forces of the material will tend to return to the setshape after being subjected to deformation by external forces. Aftershape setting, the tongue 511 is moved to its preloaded position so thatthe cross-bar 514 can be attached. Consequently, the clasp 500 can becompletely flattened for delivery through a delivery sheath and allowedto expand once deployed within the heart.

The clasp 500 is opened and closed by applying and releasing tension onan actuating means such as an actuation line, suture, wire, rod,catheter, or the like (not shown) attached to the moveable arm 530. Thesuture is inserted through an opening 542 in the moveable arm 530 andlooped around a pin 543 disposed in the opening 542. The smooth roundshape of the pin 543 allows tension to be applied to the moveable arm530 from many directions without causing the suture to wear. In certainembodiments, an intermediate suture loop is made through the opening andaround the pin and the suture is inserted through the intermediate loop.An intermediate loop of suture material reduces friction experienced bythe actuation suture relative to the friction between the actuationsuture and the clasp material. When the actuation suture is loopedaround the pin 543, both ends of the suture extend back into and throughthe delivery sheath 102 (see FIG. 1). The suture can be removed bypulling one end of the suture proximally, until the other end of thesuture pulls around the pin 543 and back into the delivery sheath.

Referring now to FIGS. 28-31, an exemplary barbed clasp 600 similar tobarbed clasps 400 and 500 is shown in a variety of bent positions toillustrate the independent movement of the layers forming the barbclasps 400, 500, and 600. The barbed clasp 600 is formed from a toplayer 602 and a bottom layer 604. The barbed clasp 600 includes amoveable arm 620, a fixed arm 622, a hinge portion 624. The moveable arm620 includes a barbed portion 626 with barbs 628. The barbed clasp 600does not include a cross-bar to prevent the moveable arm 620 from movingpast the fixed arm 622. Instead of a cross-bar, the moveable arm 620 isheld in a closed position with the fixed arm 622 by the inner paddle(not shown). To better illustrate the preloading of the clasp 600, FIGS.28-31 show the fixed arm 622 moving relative to a stationary moveablearm 620. When assembled to an implantable device, however, the moveablearm 620 would move relative to the fixed arm 622 that is attached to thedevice.

Referring now to FIGS. 28-29, the clasp 600 is shown in a preloading orshape setting condition. The fixed arm 622 is bent below the moveablearm 620 by an angle 610 before the shape setting operation is performed.Force must be applied then to return the fixed arm 622 to a parallelrelationship with the moveable arm 620. Thus, increasing the preloadingangle 610 increases the force required to move the fixed arm 622,thereby increasing the preloading spring force pinching the arms 620,622 together when the clasp 600 is closed. In other words, the greaterthe angle 610, the greater the spring force applied to captured tissueby the arms 620, 622.

Referring now to FIGS. 30-31, the clasp 600 is shown being opened to anopening angle 612. As can be seen in FIGS. 30 and 31, the beam loops ofthe hinge portion 624 tend to separate as the clasp 600 is opened.Allowing the layers 602, 604 to separate during bending decreases strainon the material, thereby further increasing the maximum opening angle612 that can be achieved before plastic deformation of the claspmaterial. As noted above, the hinge portion 624 is shaped to formsomewhat spiral or helical beam loops, thereby forming a gap or stepdistance 614 between the arms 620, 622 (FIG. 29) that allows the leaflettissue to be captured.

As the clasp 600 is opened, the layers 602, 604 in the fixed arm 622slide relative to each other. In some embodiments, holes through thefixed arm 622 are elongated so that sutures securing the fixed arm 622to the implantable device are not pinched by the sliding movement of thelayers, nor are the layers 602, 604 constrained from sliding, whichreduces strain experienced by the clasp material.

Referring now to FIGS. 32-35, exemplary barb clasps 700, 800, 900, and1000 are shown. Barb clasps 700, 800, 900, and 1000, like clasps 400,500, 600 can be used in the implantable devices 100, 200, and 300described above. Unlike barbed clasps 400, 500, 600, however, barbedclasps 700, 800, 900, and 1000 are formed by laser cutting material fromthe side of the clasp rather than from the top. Laser cutting from theside reduces the operations required to manufacture the clasp and allowsthe thickness of the clasp to be varied to vary the bending propertiesof portions of the clasp based on the function of each portion. Forexample, hinge portions may be thinner to provide more flexibility whilearms may be thickened to provide more stiffness.

Referring now to FIG. 32, a laminated barb clasp 700 is shown. The barbclasp 700 has thick and thin portions 702, 704 and is formed fromalternating spacer layers 706 and barbed layers 708 to form a laminatedstructure. The clasp 700 includes a moveable arm 720, a fixed arm 722,and a hinge portion 724. The moveable arm 720 includes a barbed portion726 having barbs 728 formed in the barbed layers 708. Forming the layers706, 708 by laser cutting from a side profile allows the barbs 728 to betapered, thereby providing a stiff barb with a sharp point. The fixedarm 722 includes holes to secure the clasp 700 to an implantable device.When assembled to an implantable device, the fixed arm 722 is extendedby the attached inner paddle, thus the native tissue is pinched betweenthe moveable arm 720 and the inner paddle of the device. The moveableand fixed arms 720, 722 are formed at an angle relative to each othersuch that an extension of the fixed arm 722 would intersect with themoveable arm 720. Attaching the fixed arm 722 to the inner paddleeffectively extends the end of the fixed arm 722 such that the innerpaddle would interfere with the moveable arm 720. The interference ofthe components causes the moveable arm 720 to be moved relative to thefixed arm 722 such that the clasp 700 is opened, thereby preloading themoveable arm 722 such that a pinch force is applied against the innerpaddle when the clasp 700 is in the closed position. Thus, a pinch forceis created between the moveable and fixed arms 720, 722 withoutshapesetting the moveable and fixed arms 720, 722 of the clasp 700.Alternatively, the individual layers are formed with the moveable andfixed arms 720, 722 parallel to each other and are then bent andshapeset such that the moveable arm 720 is biased toward the fixed arm722 when the clasp 700 is affixed to the inner paddle.

Referring now to FIGS. 33-35, exemplary barb clasps 800, 900, 1000 areshown. The clasps 800, 900, 1000 are similar in overall shape whileillustrating the variety of thicknesses possible when laser cuttingclasps from the side. The clasps 800, 900, 1000 have a thin portion 804,904, 1004 and a thick portion 802, 902, 1002. The clasps 800, 900, 1000include a moveable arm 820, 920, 1020, a fixed arm 822, 922, 1022, ahinge portion 824, 924, 1024. The moveable arm 820, 920, 1020 includes abarb portion 826, 926, 1026 having barbs (not shown) similar to thebarbs 728 of the barb portion 726 of clasp 700. As can be seen in FIGS.33-35, holes can be provided in the fixed arm 822, 922, 1022 to securethe clasp 800, 900, 1000 to an implantable device. When assembled to animplantable device, the fixed arm 822, 922, 1022 is extended by theattached inner paddle, thus the native tissue is pinched between themoveable arm 820, 920, 1020 and the inner paddle of the device.

Referring now to FIG. 36, an exemplary barbed clasp 1100 similar tobarbed clasps 400, 500, 600 is shown. Unlike barbed clasps 400, 500,600, however, barbed clasp 1100 is formed from a single layer ofmaterial that varies in thickness between a thick portion 1102 and athin portion 1104. The barbed clasp 1100 includes a fixed arm 1110, ahinge portion 1120, and a moveable arm 1130. The fixed arm 1110 includesattachment holes 1112 and an optional integrated crossbar 1114. Thehinge portion 1120 includes an arcuate hinge 1122 formed from the thinportion 1104. The moveable arm 1130 includes a barbed portion 1140 withbarbs 1144. A suture (not shown) can be attached to an eyelet 1142 nearthe barbed portion 1140 to open and close the clasp 1100.

To form the barbed clasp 1100, a sheet of material is thinned to formthe thin portion 1104. The shape of the clasp 1100 is then laser cutfrom the sheet of material so that the hinge portion 1120 is alignedwith the thin portion 1104. The barbs 1144 and fixed arm 1110 are thenbent into the position shown in FIG. 36 before shape setting. Theoptional T-shaped crossbar 1114 of the fixed arm 1110 must be twisted toinsert it through the slot in the moveable arm 1130 for shape settingand to move the arms 1110, 1130 from the preloading position to a closedposition. In certain embodiments, the optional T-shaped crossbar 1114 isomitted, is smaller, or is alternatively replaced with a relief in themoveable arm 1130, to facilitate ease of manufacture and shape setting.After the shape setting, the crossbar is twisted, moved back through theslot, and positioned on top of the thick portion 1102. The crossbar 1114is positioned in generally the same manner as the crossbar 414 (see FIG.26).

Like the clasps 400, 500 described above, the clasp 1100 can be openedfully without plastically deforming the clasp material while stillproviding pinching force when closed. Fewer steps are required tomanufacture the clasp 1100 as compared to the clasps above, as the clasp1100 is cut from a single sheet of material and no welding step isneeded to weld layers of material together.

Referring now to FIGS. 37-52, an exemplary barbed clasp 1200 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 1200 is formed from a single layer1202 of material. The barbed clasp 1200 includes a fixed arm 1210, ahinged portion 1220, and a movable arm 1230 having a barbed portion1240. The hinged portion 1220 is spring-loaded so that the fixed andmoveable arms 1210, 1230 are biased toward each other when the barbedclasp 1200 is in a closed condition. When assembled to an implantableprosthetic device, the fixed arm 1210 is attached to a portion of theprosthetic device. The clasp 1200 is opened by pulling on an actuatingmans such as an actuation line or suture attached to the moveable arm1230 until the spring force of the hinge portion 1220 is overcome.

The fixed arm 1210 is formed from a tongue 1211 of material extendingfrom the hinged portion 1220 between two side beams 1231 of the moveablearm 1230 to an end 1214. In some embodiments, the moveable arm is formedfrom a tongue of material that extends between two side beams of thefixed arm. The tongue 1211 is biased between the side beams 1231 by thehinge portion 1220 such that force must be applied to move the tongue1211 from a neutral position located beyond the side beams 1231 to apreloaded position that is nearly parallel or parallel with the sidebeams 1231, as can be seen in FIGS. 39-40E. The tongue 1211 is held inthe preloaded position when it is attached to a paddle of an implantableprosthetic device. The end 1214 of the tongue 1211 may optionally have aT-shape cross-member that engages the side beams 1231 to hold the tongue1211 in the preloaded position.

In certain embodiments, the angle between the fixed and moveable arms1210, 1230 when the tongue 1211 is in the neutral position is about 30to about 120 degrees, 40 to about 110 degrees, or about 50 to about 100degrees, or about 60 to about 90 degrees, or about 90 degrees. Thetongue 1211 includes holes 1212 for receiving sutures (not shown) thatattach the fixed arm 1210 to an implantable device.

The hinge portion 1220 is formed by a plurality of torsional springsegments 1222 arranged in a repeating pattern extending from the tongue1211 of the fixed arm 1210 to the side beams 1231 of the moveable arm1230. Each spring segment 1222 is joined with other spring segments 1222to form a repeating pattern. Joining multiple segments 1222 togetherallows the hinge portion 1220 to bend a considerable amount whileavoiding plastic deformation of the material as the individual torsionalspring segments 1222 are twisted. For example, in certain embodiments,the tongue 1211 can be pivoted from the neutral position that isapproximately 90 degrees beyond the moveable arm 1230 to a fully openposition that ranges from about 140 degrees to about 200 degrees, toabout 170 degrees to about 190 degrees, or about 180 degrees. from themoveable arm 1230 without plastically deforming the clasp material. Incertain embodiments, the clasp material can plastically deform duringopening without reducing or without substantially reducing the pinchforce exerted between the fixed and moveable arms in the closedposition. The pattern spring segments 1222 are formed from open andclosed cutouts 1224 in the hinge portion 1220. Exemplary spring segmentsand their arrangement in a pattern are described below and shown inFIGS. 51A-52.

Preloading the tongue 1211 enables the clasp 1200 to maintain a pinchingor clipping force on the native leaflet when closed while also beingable to be opened wide to more easily capture the native leaflet. Thepreloading of the tongue 1211 provides a significant advantage overprior art clips that provide little or no pinching force when closed.Additionally, closing the clasp 1200 with spring force is a significantimprovement over clips that use a one-time locking closure mechanism, asthe clasp 1200 can be repeatedly opened and closed for repositioning onthe leaflet while still maintaining sufficient pinching force whenclosed.

The barbed portion 1240 of the moveable arm 1230 includes eyelets 1242and barbs 1244. Positioning the barbed portion of the clasp 1200 at anend of the moveable arm 1230 increases the space between the barbs 1244and the fixed arm 1210 when the clasp 1200 is opened, thereby improvingthe ability of the clasp 1200 to successfully capture a leaflet duringimplantation. This distance also allows the barbs 1244 to more reliablydisengage from the leaflet for repositioning. In certain embodiments,the barbs of the clasps may be staggered longitudinally to furtherdistribute pinch forces and local leaflet stress. In certainembodiments, the ends of the barbs 1244 are further sharpened using anysuitable sharpening means.

The barbs 1244 are laterally spaced apart at the same distance from thehinge portion 1220, providing a superior distribution of pinching forceson the leaflet tissue while also making the clasp more robust to leafletcapture than barbs arranged in a longitudinal row. In some embodiments,the barbs 1244 can be staggered to further distribute pinch forces andlocal leaflet stress.

The barbs 1244 are angled away from the moveable arm 1230 at an angle1246 (FIG. 38A) such that they easily engage tissue of the nativeleaflets with minimal pinching or clipping force. During use, the barbs1244 may penetrate the native leaflet tissue, though penetration of thetissue is not necessary for the clasp 1200 to securely grasp theleaflets. The barbs 1244 extend from the moveable arm at an angle 1246of about 20 degrees to about 90 degrees, or about 40 degrees to about 70degrees, or about 50 to about 60 degrees, or about 53 degrees. The angleof the barbs 1244 provides further benefits, in that force pulling theimplant off of the native leaflet will encourage the barbs 1244 tofurther engage the tissue, thereby ensuring better retention. Retentionof the leaflet in the clasp 1200 is further improved by the position ofthe end 1214 of the fixed arm 1210 when the clasp 1200 is closed. Inthis arrangement, the tissue engaged by the barbs 1244 is pinchedagainst the moveable arm 1230 at the end 1214 location, thereby formingthe tissue into an S-shaped torturous path as it passes over the barbs1244. Thus, forces pulling the leaflet away from the clasp 1200 willencourage the tissue to further engage the barbs 1244 before theleaflets can escape. The end 1214 can optionally be shapeset with aslight bend toward the moveable arm 1230 to accentuate the S-shape ofthe tortuous path of the tissue captured between the fixed and moveablearms 1210, 1230.

The layer of material 1202 of the clasp 1200 is laser cut from a sheetof shape-memory alloy, such as Nitinol. Portions of the layer 1202, suchas the fixed arm 1210, hinge portion 1220 and barbs 1244 are bent into adesired position. The clasp 1200 is then subjected to a shape-settingprocess so that internal forces of the material will tend to return tothe set shape after being subjected to deformation by external forces.After shape setting, the tongue 1211 is moved to its preloaded, closed,or open positions to be attached to the implantable device.Consequently, the clasp 1200 can be substantially flattened in theclosed position for delivery through a delivery sheath and allowed toexpand once deployed within the heart.

The clasp 1200 is opened and closed by applying and releasing tension onan actuation line or suture (e.g., suture 2504 of FIG. 71) attached tothe moveable arm 1230. The suture is inserted through at least one ofthe eyelets 1242 located near the barbed portion 1240 of the moveablearm 1230 before returning to the delivery sheath. In certainembodiments, an intermediate suture loop is made through one or more ofthe eyelets 1242 and the actuation suture is inserted through one ormore of the intermediate loops. An intermediate loop of suture materialreduces friction experienced by the actuation suture relative to thefriction between the actuation suture and the clasp material. When thesuture is looped through the eyelet 1242 or intermediate loop, both endsof the actuation suture extend back into and through the delivery sheath102 (see, e.g., FIG. 1). The suture can be removed by pulling one end ofthe suture proximally until the other end of the suture pulls throughthe eyelet or intermediate loop and back into the delivery sheath.

Like the clasps 400,500 described above, the clasp 1200 can be openedfully without plastically deforming the clasp material while stillproviding pinching force when closed. Fewer steps are required tomanufacture the clasp 1100 as compared to the clasps above, as the clasp1200 is cut from a single sheet of material and no welding step isneeded to weld layers of material together.

Referring now to FIGS. 37-48E, the clasp 1200 is shown in variousbending positions ranging from a neutral position (FIGS. 37-38E) to afully open position (FIGS. 47-48E). Though the fixed arm 1210 is shownin different positions in FIGS. 37-48E, once installed in an implantabledevice, the moveable arm 1230 is actuated by the surgeon to moverelative to the device while the fixed arm 1210 remains stationaryrelative to the device.

FIGS. 37-38E show the clasp 1200 in the neutral position forshape-setting. During shape-setting, the tongue 1211 of the fixed arm1210 is bent to a tongue angle 1216 that is about 60 degrees to about120 degrees, or about 90 degrees below the side beams 1231 of themoveable arm 1230. After shape-setting, the tongue 1211 remains in theshape-setting or neutral position unless acted upon by forces to movethe tongue 1211 into other positions. Thus, when the tongue 1211 ismoved to a preloading or closed position (FIGS. 39-40E) internal forcesof the clasp material are exerted in the closing direction, therebygenerating a pinching force when the clasp 1200 is in the closed orpreloaded condition. During implantation of a medical device includingthe clasp 1200, the moveable arm 1230 is actuated with a suture (notshown) to change the angle 1216 between the fixed and moveable arms1210, 1230. The clasp 1200 is shown in a one-quarter open condition inFIGS. 41-42E, a half open condition in FIGS. 43-44E, a three-quarteropen condition in FIGS. 45-46E, and a fully open condition in FIGS.47-48E. The angle 1216 between the fixed and moveable arms 1210, 1230 inthe fully open position may be about 140 degrees to about 200 degrees,to about 170 degrees to about 190 degrees, or about 180 degrees. Thatis, the clasp 1200 is capable of being opened substantially completelyflat without plastic deformation of the clasp material.

Referring now to FIGS. 49-50, the layer 1202 of material for forming theclasp 1200 is shown in a pre-shape setting condition, that is, in asubstantially flat condition after being laser cut from a sheet ofmaterial. FIG. 50 in particular clearly shows the repeating nature ofthe pattern of spring segments 1222 and cutouts 1224 that form the hingeportion 1220.

Referring now to FIGS. 51A-51D, exemplary torsional spring segments1300, 1400, 1500, 1600 for a patterned hinge portion (e.g., hingeportion 1220 of the clasp 1200) are shown. The spring segments 1300,1400, 1500, 1600 are arrangeable in a repeating pattern that is cut outof a single piece so that there are no physical seams between theindividual segments. Thus, the shape of the spring segments 1300, 1400,1500, 1600 is defined by the cutouts in the hinge portion and imaginaryboundaries at the “joints” between segments.

Referring now to FIG. 51A, the spring segment 1300 is formed by cutouts1301 made in a layer 1302 of material resulting in a substantiallyrotationally symmetric, S-like shape. Each spring segment 1300 extendsfrom a first end 1310 to a second end 1320 between a first side 1330 anda second side 1340. A first end joining location 1312 is located at thefirst end 1310 adjacent the first side 1330. A first side joininglocation 1332 is located at the first side 1330 adjacent the first end1310. A second end joining location 1322 is located at the second end1320 adjacent the second side 1340. A second side joining location 1342is located at the second side 1340 adjacent the second end 1320. Sidesurface 1304 extend between the first end joining location 1312 and thesecond side joining location 1342, and between the second end joininglocation 1322 and the first side joining location 1332. An inner corner1306 is formed near each side joining location 1332, 1342.

Referring now to FIGS. 51B-51D, spring segments 1400, 1500, 1600 areshown. These spring segments 1400, 1500, 1600 are similar in structureto the spring segment 1300 described above, though spring segments 1400,1500, 1600 include an outer corner 1408, 1508, 1608 near each endjoining location opposite the side joining location. The shapes of thespring segments 1300, 1400, 1500, 1600 vary in the size and shape of theside surfaces 1304, 1404, 1504, 1604, rounded inner corners 1306, 1406,1506, 1606 and rounded outer corners 1408, 1508, 1608. For example, theside surfaces 1304, 1404 are substantially straight, while the sidesurfaces 1504, 1604 are concave. These differences in shape change thestress distribution in hinge portions formed from a pattern of thedifferently shaped spring segments.

Referring now to FIG. 52, an exemplary spring grouping 1700 of springsegments 1300 is shown. As can be seen in FIG. 52, side joininglocations 1332, 1342 are joined to other side joining locations 1332,1342 and end joining locations 1312, 1322 are joined to other endjoining locations 1312, 1322. The substantially rotationally symmetricshape of the spring segments 1300 allows either end 1310, 1320 or side1330, 1340 of one segment to be joined to either end 1310, 1320 or side1330, 1340 of another segment. Various patterns may then be formed, suchas the H-pattern formed by the grouping 1700 in FIG. 52. While thesegments 1300, 1400, 1500, 1600 are substantially rotationallysymmetric, individual segments in a pattern of segments may be modifiedto form rounded outer edges of a hinge portion or to adapt to the fixedor moveable arm of a clasp.

When the spring grouping 1700 is subjected to a bending force 1710 eachof the segments 1300 is twisted in the direction indicated by the arrows1720. Consequently, the individual spring segments 1300 are subjected totorsional strain and not bending strain. One can also see that thedeformation of the material 1302 is reduced relative to the bending of aflat sheet of material being bent in a similar manner while maintainingthe spring force of the hinge portion of the clasp. As a result, a hingeportion formed from a pattern of torsional spring segments is strong andflexible.

To form a patterned hinge portion, such as the hinge portion 1220described above, a pattern comprising plurality of spring segments arearranged in rows and columns. The spring segments are arranged withtheir longitudinal and lateral axes in the same orientation, as can beseen in FIGS. 49-50 and 52. In certain embodiments, the spring segmentsmay be rotated relative to each other to form different spring patterns.The spring segments are organized into columns and rows. Columns aredefined along the longitudinal axis of the clasp, while rows are definedalong the lateral axis of the clasp. Thus, a column of spring segmentsis as wide as the longest dimension of an individual spring segment,while a row of spring segments has a height equal to the shortestdimension of an individual spring segment. For example, the clasp 1200shown in FIG. 50 includes three columns and seven rows of springsegments (not including partial rows connecting the hinge portion to thefixed and moveable arms). Where the ends of segments border an edge ofthe clasp, two segments in adjacent rows are joined together at onelocation, forming a U-shaped grouping. Individual spring segments orgroupings of spring segments may be modified away from their rotationalsymmetry to increase the smoothness and/or robustness of the edges ofthe hinge portion. Where the ends of segments are located at anintersection of two columns, the segments may join up to three othersegments, forming an X-shaped grouping, like the grouping 1700 shown inFIG. 62. The patterned hinge may include any suitable number of rows andcolumns of spring segments. The size and shape of each segment may beadjusted to adjust the spring parameters of the patterned hinge. Thesize and shape of the spring segments may be uniform throughout thepatterned hinge or may vary based on the location of the spring segmentwithin the pattern.

Referring now to FIGS. 53-55, an exemplary barb clasp 1800 is shown thatis cut from a tube of material 1802 using four-axis laser cutting (X, Y,Z, and rotation axes) and five-axis laser cutting (X, Y, Z, and twotilt-axes for the laser head). The tube can first be cut into segmentsand then each segment is cut in generally the same way that a flat pieceof stock or blank material is cut; that is, the tube provides a curvedblank instead of a flat blank. The additional degrees of freedom of thelaser cutter allow the tube to be rotated or the head of the lasercutter to be tilted during laser cutting. Rotating the tube or tiltingthe laser cutting head allows the barbs to be cut in the sharper barbconfiguration shown in FIG. 55 without requiring a separate sharpeningoperation. The clasp 1800 is similar in structure to the clasp 1200,described in detail above. The tube of material 802 has an inner radius1804, an inner surface 1801, and an outer surface 1803. Cutting theclasp 1800 from a tube of material 1802 provides a cupped or concaveprofile when viewed from the end, as shown in FIG. 54. One effect of theconcave profile is that the elongated portions of the fixed and movingarms 1810, 1830 increasing their stiffness, without substantiallyimpacting the flexibility of the hinge portion 1820. The concave profilealso results in barbs 1844 with sharper points or tips 1846 without aseparate sharpening operation—i.e, the barbs are formed with a bevelededge without sharpening. The sharp points 1846 enable improvedengagement with the native leaflet tissue. Referring to FIG. 55, thesharp points 1846 are formed during laser cutting because the cuttingplanes that form first and second sides 1847, 1848 of the barbs 1844 tointersect at the tip 1846, thereby forming a triangular pyramid shapethat comes to a point that is not possible when the cutting planes thatform the sides of the barb are parallel and do not intersect. Thus, thebarbs 1844 of the clasp 1800 have a strong base 1845 and a sharp point1846 in a single layer of material, without any secondary sharpeningoperation.

Referring now to FIG. 56, an exemplary clasp 1900 is shown. The clasp1900 is similar in structure to the clasp 1200, described in detailabove with a differently structured hinge portion 1920. The hingeportion 1920 includes a plurality of beams 1922 formed by a series ofelongated cuts 1924. Referring now to FIGS. 56A-56B, alternateembodiments of the beams 1922 of the hinge portion 1920 are shown. FIG.56A shows the rectangular beam 1922 having a bent portion 1926. FIG. 56Bshows the rectangular beam 1922 having a bent portion 1926 that is alsotwisted about 90 degrees such that the cross-section of the beam in thebent portion 1926 is perpendicular to the portions of the beam 1922 atits ends. Twisting the beam 1922, as shown in FIG. 56B, reduces thebending strain in the beam 1922 thereby increasing its flexibility.

Referring now to FIGS. 57-58, an exemplary barbed clasp 2000 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 2000 includes a fixed arm 2010 that isattached to the implantable device. The barbed clasp 2000 differs fromother clasps in that the clasp 2000 includes a plurality of movable arms2030 that each have a hinged portion 2020 and a barbed portion 2040having a single barb 2042. The independent arms 2030 of the clasp 2000individually pinch the tissue of the native leaflet which allows forimproved engagement of tissue that is not uniform in thickness. The arms2030 can also be shape set in a wide or spread out arrangement andcrimped down into a narrow configuration for deployment so that thebarbs 2042 can be spaced apart laterally more than would be possible ifthe arms were rigidly connected. In certain embodiments, the arms 2030include an optional hole or notch (not shown) that can be engaged by anactuation suture to cinch the arms 2030 together during deployment.

The fixed arm 2010 is formed from a tongue 2011 from which beams 2031that form the moveable arms 2030 extend. The hinge portions 2020 areformed by bending each of the beams 2031 to form a bent portion 2022.The hinged portions 2020 are spring-loaded so that the fixed andmoveable arms 2010, 2030 are biased toward each other when the barbedclasp 2000 is in a closed condition. In certain embodiments, the tongue2011 is formed from a wide plate of material to provide a larger lateralarea as a pinching location for the independent arms 2030.

The barbed clasp 2000 is laser cut from a layer 2002 of shape-memoryalloy, such as Nitinol. As is shown in FIG. 57A, the barbs 2042 lay flatin the same plane as the rest of the clasp 2000 when cut out of thelayer 2002 of material. The moveable arms 2030 and barbs 2040 are thenbent and twisted into the shape shown in FIG. 57 and are then subjectedto a shape setting process. As noted above, the independent arms 2030 ofthe clasp 2000 can be shape set as wide or narrow as desired. In certainembodiments individual arms 2030 may be longer or shorter than others,and the spacing of the arms 2030 may vary or be uniform.

Cutting the barbs 2042 out of the sheet of material and then twistingthem into position also allows larger barbs of a variety of shapes to beformed. In certain embodiments, the barbed portions 2040 may includemultiple smaller barbs arranged in series that may or may not be facingin the same direction. In certain embodiments, the ends of the barbs2042 are further sharpened using any suitable sharpening means. Incertain embodiments, the hinge portions 2020 of the beams 2031 includetwisted portions 2024. The twisted portions 2024 may act as torsionalsprings that resist lateral forces applied to the ends of the barbs2042, thereby helping to maintain the alignment of the barbs 2042 whenengaging the tissue of the native leaflets.

Referring now to FIGS. 59-63, an exemplary clasp 2100 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The clasp 2100 is expandable between a collapsedcondition and an expanded condition and is shape set in the expandedcondition so that the clasp 2100 automatically expands from thecollapsed condition to the expanded condition. As can be seen in FIG.61A, the clasp 2100 can be deployed from a delivery sheath 2150 in thecollapsed condition and allowed to self-expand into the expandedcondition.

The clasp 2100 has many features that are similar to the clasp 1200,described in detail above, such as a patterned hinge portion 2120 formedby a plurality of spring segments 2122 and cutouts 2124 and a fixed arm2110 that includes a tongue 2111 having holes 2112 for attaching thefixed arm 2110 to the implantable device and an end 2114 having aT-shape to retain the fixed arm 2110 in a preloaded position. The clasp2100 also has a moveable arm 2130 that includes a barbed portion 2140with a plurality of barbs 2142.

The hoop-like shape of the moveable arm 2130 provides for a wider barbedportion 2140 that can include more barbs 2142 with the same or greaterlateral spacing than other clasps. The wider spacing of the barbs 2142improves capture of the native leaflets. In certain embodiments, thehoop shape of the moveable arm 2130 is similar to the shape of wideouter paddles of an implantable device so that pinching forces of thepaddles are spread out evenly on the barbs, further improving theretention of the native leaflets. Some of the barbs 2142 may also belongitudinally staggered as a result of their position on the hoop-likeshape of the moveable arm 2130. In certain embodiments, the ends of thebarbs 2042 are further sharpened using any suitable sharpening means. Incertain embodiments, the tongue 2111 is formed from a wide plate ofmaterial to provide a larger lateral area as a pinching location.

The moveable arm 2130 is provided in the shape of a hoop or loop. Themoveable arm 2130 includes side beams 2131 that are thinner and moreflexible, particularly in the lateral direction, than the side beams1231 of the clasp 1200 described above. The side beams 2131 include afirst hinge portion 2132 arranged toward the proximate end of themoveable arm 2130 and a second hinge portion 2136 arranged at the distalend of the moveable arm 2130. The first hinge portion 2132 is formed byone or more bends in the side beams 2132. In certain embodiments, thesecond hinge portion 2136 includes a thinner—and therefore moreflexible—portion to reduce the force required to collapse the clasp2100. The moveable arm 2130 includes holes 2134 arranged between thefirst and second hinge portions 2132, 2136 for receiving the actuationsutures 2152 that are used to collapse the moveable arm 2130. The holes2134 are arranged further laterally from the center of the clasp 2130than the hinge portions 2132, 2136 to provide mechanical advantage whenforce is applied via the sutures 2152. In certain embodiments, the holes2134 are located at the lateral-most location of the side beams 2131.

The rounded hoop shape of the clasp 2100 allows the clasp 2100 to becollapse by merely retracting the clasp 2100 into the delivery sheath.In certain embodiments, the expansion and contraction of the clasp 2100is controlled by actuation sutures 2152. The sutures 2152 may be routedthrough an aperture 2156 of a guide 2154 to holes 2134 in the moveablearm 2130 to control the direction in which the force applied along thesuture 2152 is applied to cinch the moveable arm 2130 into a collapsedposition. For example, arranging the guide 2154 closer to the connectionpoint to the sutures 2152 to the clasp 2100 causes the forces applied tothe clasp 2100 by the sutures 2152 to be directed in a more lateralrather than longitudinal direction. Alternatively, as can be seen inFIG. 61B, a single suture loop 2153 can be routed through the aperture2156 of the guide 2154, through each of the holes 2134 in the moveablearm 2130, and then back through the guide 2154 so that actuation of thesingle loop 2153 cinches the moveable arm 2130 into a collapsedposition.

Referring now to FIGS. 64-68, an exemplary barbed clasp 2200 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 2200 includes elements of clasps 1200,2000 described above. The barbed clasp 2200 includes a fixed arm 2210that is attached to the implantable device and a hinge portion 2220 thatallows the clasp 2200 to open and close. The hinge portion 2220 isformed from a repeating pattern of spring segments 2222 and cutouts2224, like that of the clasp 1200.

The barbed clasp 2200 also includes features similar to the clasp 2000,such as a plurality of independent movable arms 2230 that each have abarbed portion 2240 having a single barb 2244. The independent arms 2230of the clasp 2200 individually pinch the tissue of the native leafletwhich allows for improved engagement of tissue that is not uniform inthickness. The arms 2230 can also be shape set in a wide or spread outarrangement and crimped down into a narrow configuration for deploymentso that the barbs 2244 can be spaced apart laterally more than would bepossible if the arms were rigidly connected. The barbed portion 2240 ofeach arm 2230 includes a hole 2242 for receiving an actuation suture2252 (FIG. 65A).

The clasp 2200 is expandable between a collapsed condition and anexpanded condition and is shape set in the expanded condition so thatthe clasp 2200 automatically expands from the collapsed condition to theexpanded condition. As can be seen in FIG. 65A, the clasp 2200 can bedeployed from a delivery sheath 2250 in the collapsed condition andallowed to self-expand into the expanded condition. The expansion andcontraction of the clasp 2200 is controlled by the actuation suture 2252that cinches the independent arms 2230 together to collapse the clasp2200 so that it fits within the delivery sheath 2250. In someembodiments, the independent arms collapse together by merely retractingthe clasp 2100 into the delivery sheath.

The fixed arm 2210 is formed from a tongue 2211 extending from the hingeportion 2220 to an end 2214. The tongue 2211 includes holes 2212 forsecuring the tongue 2211 to the implantable device. In certainembodiments, the tongue 2211 is formed from a wide plate of material toprovide a larger lateral area as a pinching location. In certainembodiments, the end 2214 of the tongue 2211 includes a T-shapecross-member like that of clasp 2100.

The barbed clasp 2200 is laser cut from a layer 2202 of shape-memoryalloy, such as Nitinol. Like the clasp 2100 shown in FIG. 57A, the barbs2242 lay flat in the same plane as the rest of the clasp 2200 when cutout of the layer 2202 of material. The moveable arms 2230 and barbedportions 2240 are then bent and twisted into the shape shown in FIGS.64-68 and are then subjected to a shape setting process. In someembodiments, the barbs of the independent arms are [?] cut so that thebarbs are bent upwards like the barbs of clasp 1200, thereby notrequiring the twisting of the independent arms. As noted above, theindependent arms 2230 of the clasp 2200 can be shape set as wide ornarrow as desired. In certain embodiments, individual arms 2230 may belonger or shorter than others, and the spacing of the arms 2230 may varyor be uniform.

Cutting the barbs 2244 out of the sheet of material and then twistingthem into position also allows larger barbs of a variety of shapes to beformed. In certain embodiments, the barbed portions 2240 may includemultiple smaller barbs arranged in series that may or may not be facingin the same direction. In certain embodiments, the ends of the barbs2244 are further sharpened using any suitable sharpening means. Incertain embodiments, the beams 2231 include twisted portions 2232. Thetwisted portions 2232 may act as torsional springs that resist lateralforces applied to the ends of the barbs 2244, thereby helping tomaintain the alignment of the barbs 2244 when engaging the tissue of thenative leaflets.

Referring now to FIGS. 69-73B, various arrangements for attaching anactuating suture to exemplary barb clasps are shown. In theseembodiments, an intermediate suture loop is made through one or more ofthe eyelets in the barbed clasp and the actuation suture is insertedthrough one or more of the intermediate loops. Connecting to the claspthrough an intermediate loop of suture material reduces frictionexperienced by the actuation suture relative to the friction between theactuation suture and the clasp material. Both ends of the actuationsuture extend back into and through the delivery sheath (not shown). Thesuture can be removed by pulling one end of the suture proximally untilthe other end of the suture pulls through the eyelet or intermediateloop and back into the delivery sheath.

Referring now to FIG. 69, an exemplary suture arrangement 2300 is shownattached to the barb clasp 400 described above. The suture arrangement2300 includes an intermediate suture loop 2302 inserted through theeyelet 442 and around the end of the barbed portion 440. Alternatively,the intermediate suture loop 2302 may be inserted through the eyelet 442and between the side beams of the moveable arm. An actuation suture 2304is threaded from the delivery sheath through the intermediate sutureloop 2302 and back into the delivery sheath. Tension applied to theactuation suture 2304 opens the clasp 400 when the spring forces keepingthe clasp 400 closed are overcome. Releasing tension on the actuationsuture 2304 allows the clasp 400 to spring shut. The rounded shape ofthe barbed portion 440 of the clasp 400 prohibits the clasp 400 fromcatching on native tissue or other portions of the implantable device.

Referring now to FIGS. 70A-70B, an exemplary suture arrangement 2400 isshown attached to the barb clasp 1200 described above. The suturearrangement 2400 includes an intermediate suture loop 2402 insertedthrough the center eyelet 1242 and between the side beams 1231 of themoveable arm 1230. An actuation suture 2404 is threaded from thedelivery sheath through the intermediate suture loop 2402 and back intothe delivery sheath. Tension applied to the actuation suture 2404 opensthe clasp 1200 when the spring forces keeping the clasp 1200 closed areovercome. Releasing tension on the actuation suture 2404 allows theclasp 1200 to spring shut.

FIG. 70A is a side view of the suture arrangement 2400 showing that agap or recess 2406 may form between the end of the clasp and theactuating suture 2404 of the suture arrangement 2400 described above. Inparticular, the gap 2406 may form when the actuation suture 2404 is atan angle with the barbed portion of the clasp 1200. FIG. 70B is a frontview of the suture arrangement 2400 showing that side gaps or recesses2408 are formed between the actuation suture 2404 and the sides of thebarbed portion 1240 of the clasp 1200. Under certain conditions, thegaps or recesses 2406, 2408 may become catch points—i.e., a locationthat has a potential to catch or snag native tissue or other portions ofthe implantable device during deployment and installation and/or on acatheter wall during retrieval. In particular, sharp angles and edgesmay become catch points. Rounding the corners of the clasp 1200, as canbe seen in FIG. 70B, reduces the chance that the clasp 1200 will catch.In some embodiments, the device does not include any recesses having adepth greater than one third of the width of the device.

Referring now to FIG. 71, a front view of an exemplary suturearrangement 2500 is shown attached to the barb clasp 1200 describedabove. The suture arrangement 2500 includes an intermediate suture loop2502 inserted through the center eyelet 1242 and around the end of thebarbed portion 1240. An actuation suture 2504 is threaded from thedelivery sheath through the intermediate suture loop 2502 and back intothe delivery sheath. Tension applied to the actuation suture 2504 opensthe clasp 1200 when the spring forces keeping the clasp 1200 closed areovercome. Releasing tension on the actuation suture 2504 allows theclasp 1200 to spring shut.

Forming the intermediate suture loop 2502 around the end of the barbedportion 1240 eliminates the possibility that a gap (e.g., the gap 2406shown in FIG. 70A) will form between the actuation suture and the clasp.Like the suture arrangement 2400 described above and shown in FIG. 70B,FIG. 71 shows that side gaps 2508 are formed between the actuationsuture 2504 and the sides of the barbed portion 1240 of the clasp 1200.Under certain conditions, the gaps 2508 may become catch points—i.e., alocation that has a potential to catch or snag native tissue or otherportions of the implantable device during deployment and installationand/or on the catheter during retrieval. In particular, sharp angles andedges may become catch points. Rounding the corners of the clasp 1200,as can be seen in FIG. 71, reduces the chance that the clasp 1200 willcatch on native tissue or other portions of the device.

Referring now to FIGS. 72-73B, an exemplary suture arrangement 2600 isshown attached to the barb clasp 1200 described above. The suturearrangement 2600 includes intermediate suture loops 2602 insertedthrough the eyelets 1242 proximate the sides of the clasp 1200 andaround the end of the barbed portion 1240. An actuation suture 2604 isthreaded from the delivery sheath through the intermediate suture loops2602 and back into the delivery sheath. Tension applied to the actuationsuture 2604 opens the clasp 1200 when the spring forces keeping theclasp 1200 closed are overcome. Releasing tension on the actuationsuture 2604 allows the clasp 1200 to spring shut.

The suture arrangement 2600 reduces or eliminates the gaps shown inFIGS. 70A-71 that can become catch points. Forming the intermediatesuture loops 2602 around the end of the barbed portion 1240 eliminatesthe possibility of a gap, such as the gap 2406 shown in FIG. 70A, fromforming between the clasp 1200 and the actuation suture 2604. The suturearrangement 2600 also reduces or eliminates side gaps, such as the sidegaps 2508 shown in FIGS. 70B and 71, between the actuation suture 2604and the sides of the clasp 1200.

Referring now to FIGS. 74A-75, exemplary barb clasps and implantabledevices are shown. As noted above, catch points are locations on theimplantable device that have a potential to catch or snag native tissue,other portions of the implantable device, and/or delivery catheterduring deployment and installation and/or during recapture or retrieval.In addition to catch points that may be formed on individual componentsof the implantable device, such as the catch points described above,catch points may also be formed by the assembly of two or morecomponents.

Referring now to FIGS. 74A-74B, an exemplary implantable device 2700 isshown assembled with two barb clasps 400. The barb clasps 400 areattached to inner paddles 2720 of the implantable device 2700 thatextend from a coaption element 2710. A suture arrangement 2730 includesintermediate suture loops 2732 attached to the barbed portion 440 of theclasps 400, and actuation sutures 2734 extending from a delivery sheath2702, through the intermediate suture loops 2732, and back into thesheath 2702. When the clasps 400 are in a closed condition, the offsetof the hinge portions 420 forms a gap 2740 between the clasps 400 andcoaption element 2710 that can become a catch point. As can be seen inFIG. 74B, the gap 2740 is reduced or eliminated when the clasps 400 areopened partially, though the overall width of the device 2700 increasesbecause of the opening of the clasps 400. As such, the catch point canbe eliminated during recapture or retrieval by partially opening theclasps 400 as shown in FIG. 74B. Partially opening the clasps whenretracting the device into the sheath has an additional benefit ofcausing the actuation lines or sutures to engage an opening 2703 of thedelivery sheath 2702, thereby causing the opening 2703 to flair open andprovide a larger opening through which the device 2700 can be withdrawn.Suture configurations like those shown in FIGS. 70B and 71 engage theopening 2703 in two locations as the sutures extend from the clasps intwo locations, thereby widening the opening 2703 in a substantiallydiamond shape. Suture configurations like those shown in FIG. 72 engagethe opening 2703 in four locations because the sutures extend from theclasps in four locations, thereby widening the opening 2703 in asubstantially rectangular shape. The actuation sutures 2734 can berelaxed after the hinge portions 420 are in the catheter.

Referring now to FIG. 75, an exemplary implantable device 2800 is shownassembled with two barb clasps 1200. The barb clasps 1200 are attachedto inner paddles 2820 of the implantable device 2800 that extend from acoaption element 2810. A suture arrangement 2830 includes intermediatesuture loops 2832 attached to the barbed portion 1240 of the clasps1200, and actuation sutures 2834 extending from a delivery sheath 2802,through the intermediate suture loops 2832, and back into the sheath2802. The round shape of the hinge portion 1220 of the clasp 1200prevents a catch point from forming at an intersection 2840 between thehinge portion 1220 and the coaption element 2810. Thus, the shape of theclasp 1200 reduces or eliminates gaps, such as the gap 2740 shown inFIG. 74B that may become catch points, without needing to partially openthe clasps 1200 during retrieval or recapture.

In certain embodiments, rather than an intermediate suture loop, theactuation line or suture is attached to a portion of a coveringsurrounding a clasp of an implantable device. For example, the actuationline or suture may be threaded through a loop or openings in thecovering. The covering may be formed from a flexible material that maybe a mesh, woven, braided, or formed in any other suitable way. Theflexible material may be cloth, shape-memory alloy wire—such asNitinol—to provide shape setting capability, or any other flexiblematerial suitable for implantation in the human body.

Referring now to FIG. 76, a side view of an exemplary barb clasp 2900 isshown. While the clasp 2900 is shown in the shape of the clasp 1200described above, the clasp 2900 can have any shape suitable for use as abarbed clasp formed from laminated layers of material, such as any ofthe clasps described above. The clasp 2900 has a fixed arm 2910, hingedportion 2920, moveable arm 2930, and barbed portion 2940. The clasp 2900is formed from a first layer 2902 and a second layer 2904 of material.The layers 2902, 2904 may be formed from similar or different materials,and may have the same or different thicknesses. In certain embodiments,additional layers of material may also be provided.

Referring now to FIG. 77, a side view of an exemplary double-ended barbclasp 3000 is shown. The double-ended clasp 3000 has a fixed arm 3010with hinge portions 3020 and moveable arms 3030 extending from bothends. Each moveable arm 3030 includes a barbed portion 3040 including atleast one barb 3042. While the barbs 3042 are shown facing outwards, inother embodiments the barbs 3042 face inwards. The clasp 3000 is formedfrom first and second layers of material 3002, 3004, though, in certainembodiments, the clasp is formed from a single layer, and in certainother embodiments, is formed from more than two layers. The hingeportions 3020, movable arms 3030, and barbed portions 3040 may be formedin the shape of any of the clasps described above.

Referring now to FIGS. 78-79, an exemplary barbed clasp 3102 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The barbed clasp 3102 includes elements of clasp 1200described above. The barbed clasp 3102 includes a fixed arm 3110 that isattached to the implantable device and a hinge portion 3120 that allowsthe clasp 3102 to open and close. The hinge portion 3120 is formed froma repeating pattern of spring segments 3122 and cutouts 3124, like thatof the clasp 1200. The barbed clasp 3102 also includes a pair ofindependent first and second movable arms 3130, 3132 extending from thehinge portion 3120 to a barbed portion 3140 having barbs 3144.

The fixed arm 3110 is formed from a tongue 3111 extending from the hingeportion 3120 to an end 3114. The tongue 3111 includes holes 3112 forsecuring the tongue 3111 to the implantable device. In certainembodiments, the tongue 3111 is formed from a wide plate of material toprovide a larger lateral area as a pinching location. In certainembodiments, the end 3114 of the tongue 3111 includes a T-shapecross-member like that of clasp 3102.

The moveable arms 3130, 3132 of the clasp 3102 individually pinch thetissue of the native leaflet which allows for improved engagement oftissue that is not uniform in thickness. In some embodiments, themoveable arms 3130, 3132 are formed from a single moveable arm similarto the moveable arm 1230 of clasp 1200 that is separated into first andsecond moveable arms 3130, 3132 by a cut 3148 so that the first andsecond moveable arms 3130, 3132 are allowed to open and closeindependent from each other. In some embodiments, the hinge portion 3120is also separated into first and second hinge portions (not shown).

Referring now to FIG. 79, an exemplary implantable device 3100 is shownassembled with two barb clasps 3102. The barb clasps 3102 are attachedto inner paddles 3108 of the implantable device 3100 that extend from acoaption element 3106. An actuation arrangement 3150 includesintermediate suture loops 3152 attached to holes 3146 in the barbedportion 3140 of the first and second moveable arms 3130, 3132 and firstand second actuation sutures 3154, 3156. The first and second actuationsutures 3154, 3156 extend from the delivery sheath 3104, through theintermediate suture loops 3152, and back into the delivery sheath 3104.Each of the moveable arms 3130, 3132 can be separately opened byapplying tension to the first and second actuation sutures 3154, 3156,respectively. Opening the first and second moveable arms 3130, 3132separately allows the grip of the clasp 3102 on native tissue to beadjusted based on the thickness of the tissue and the orientation of theclasp 3100.

Referring now to FIGS. 80A-80E, an exemplary barbed clasp 3200 for usein implantable prosthetic devices, such as devices 100, 200, 300described above, is shown. The clasp 3200 is configured to place atensioning force on the native tissue when the implantable prostheticdevice—e.g., any device described in the present application—is attachedto the native tissue. Like the barbed clasps described above, the barbedclasp 3200 includes a fixed arm 3210, a hinge portion 3220, and amoveable arm 3230 having a barbed portion 3240. The fixed arm 3210 ofthe clasp 3200 is slideably connected to a paddle 3202 of an implantabledevice such that the clasp 3200 can be moved along the paddle 3202 inthe direction 3204. For example, an actuation line 3250 can be used tomove the clasp 3200 along the paddle 3202 in the direction 3204. Theactuation line 3250 can also be used move the moveable arm 3230 betweenthe closed position (as shown in FIG. 80A) and the open position (asshown in FIG. 80B). The actuation line 3250 can take any form describedin the present application. In some embodiments, the clasp 3200 includesan optional biasing member 3260 (e.g., a spring) configured to maintainthe clasp 3200 in a desired position along the paddle 3202 (e.g., theposition shown in FIGS. 80A and 80E).

Referring to FIG. 80A, the clasp 3200 is shown in a first position onthe paddle 3202 and in a closed position. Referring to FIG. 80B, theclasp 3200 is shown after the moveable arm 3230 has been moved in adirection 3203 to an open position by the actuation line 3250. Referringto FIG. 80C, the clasp 3200 is shown after having been moved along thepaddle 3202 in a direction 3205 to a second position. In someembodiments, the clasp 3200 is moved along the paddle 3202 in thedirection 3205 by the actuation line 3250 or a separate mechanism. Inembodiments that include the biasing member 3260, enough force isapplied to the clasp 3200 to move the clasp 3200 in the direction 3205,causing the biasing member 3260 to expand and create a tension force onthe clasp 3200 in a direction 3206 opposite to the direction 3205. Whilethe illustrated embodiment shows the clasp 3200 being moved to an openposition (as shown in FIG. 80B) prior to the clasp 3200 being movedalong the paddle 3202 in the direction 3205 to the second position (asshown in FIG. 80C), it should be understood that clasp 3200 can be movedin the direction 3205 to the second position prior to the moveable arm3230 of the clasp 3200 being moved in the direction 3203 to an openposition or the movements can be simultaneous. Referring to FIG. 80D,the moveable arm 3230 is moved to a closed position in the direction3207 by the actuation line 3250 to secure the barbed portion 3240 of theclasp 3200 to valve tissue (not shown). In the position shown in FIG.80D, the biasing member 3260 is being maintained in an extended position(e.g., as a result of the force applied to the clasp 3200 by theactuation line 3250, or another mechanism, to keep the clasp 3200 in thesecond position), which means the biasing member 3260 is placing atensioning force on the clasp 3200 in the direction 3206. Referring toFIG. 80E, after the barbed portion 3240 of the clasp 3200 is secured tothe native tissue, the force maintaining the clasp 3200 in the secondposition is released, which causes the tensioning force applied by thebiasing member 3260 to move the clasp 3200 along the paddle 3202 in thedirection 3208. The movement of the clasp 3200 in the direction 3208causes the barbed portion 3240 to create a tensioning force on thenative tissue in the direction 3209. This tensioning force on the nativetissue allows the implantable device to maintain a secure connection tothe native tissue.

Referring now to FIGS. 81A-81C, an exemplary barbed clasp 3300 for usein implantable prosthetic devices, such as devices 100, 200, 300described above, is shown. The clasp 3300 is configured to place atensioning force on the native tissue when the implantable prostheticdevice—e.g., any device described in the present application—is attachedto the native tissue. Like the barbed clasps described above, the barbedclasp 3300 includes a fixed arm 3310, a hinge portion 3320, and amoveable arm 3330 having a barbed portion 3340. The moveable arm 3330includes a flexible portion 3332 arranged between the hinge portion 3320and the barbed portion 3340. The flexible portion 3332 may comprise, forexample, a cutout in the moveable arm 3330, a different material thanthe remainder of the moveable arm 3330, or can take any other suitableform that allows the flexible portion 3332 to be more flexible than theremainder of the moveable arm 3330. In some embodiments, the flexibleportion 3332 is omitted and an actuation mechanism 3350 is still capableof flexing the barbed portion 3340 of the moveable arm 3330 asillustrated by FIGS. 81A-81C.

The actuation mechanism 3350 includes an actuation line 3352 (e.g., asuture) and a push-pull link 3354 configured to receive the line 3352.The push-pull link 3354 can be a catheter, a wire with a loop (as shownin FIG. 82), or any other link that is capable of receiving the line3352 and pushing or pulling the moveable arm 3330 of the clasp 3300. Theactuation line 3352 extends at a first end 3351 from a delivery sheath(not shown) and is removably attached to the moveable arm 3330 at afirst connection point 3356 arranged proximate the barbed portion 3340.The actuation line 3352 also extends from the first connection point3356 and is removably attached to the moveable arm 3330 at a secondconnection point 3358 arranged between the flexible portion 3332 and thehinge portion 3320. The actuation line 3352 then extends from the secondconnection point 3358 and through the push-pull link 3354 at a secondend 3353.

Referring to FIG. 81A, the clasp 3300 is shown in an open position withnative tissue 3302 disposed in an opening 3304 between the moveable arm3330 and the fixed arm 3310. The clasp 3300 can be moved to the openposition by pulling on the line 3352. Referring to FIG. 81B, the link3354 and the line 3352 of the actuation mechanism 3350 is used to movethe moveable arm 3330 in the closing direction 3306 to the closedposition and flex the barbed portion 3340 in the opening direction 3308.In doing so, the first end 3351 of the line 3352 is pulled in theopening direction 3308 while the link 3354 is pushed in the closingdirection 3306 such that the barbed portion 3340 of the moveable arm3330 pivots or flexes at the flexible portion 3332 in the upwarddirection 3303 as it opens. Still referring to FIG. 81B, the link 3354and the line 3352 are moved such that the barbed portion 3340 engages orpierces the native tissue 3302 as the moveable arm 3330 is moved intothe closed position and the barbed portion 3340 is in the flexedposition.

Referring now to FIG. 81C, the first end 3351 of the line 3352 isreleased, allowing the barbed portion 3340 of the moveable arm 3330 topivot about the flexible portion 3332. As the barbed portion 3340pivots, the native tissue 3302 is retracted in the downward or inwarddirection 3305, thereby creating a tensioning force on the native tissuein the inward direction 3305. After the moveable arm 3330 is secured tothe native tissue 3302 (as shown in FIG. 81C) the link 3354 and the line3352 are removed from the clasp 3300.

Referring now to FIG. 82, an actuation mechanism 3400 for use inimplantable prosthetic devices, such as devices 100, 200, 300 describedabove, is shown. The mechanism 3400 includes first and second controlmembers 3410, 3420 that extend from a delivery device 3402. The deliverydevice 3402 may be any suitable device, such as a sheath or catheter.The first and second control members 3410, 3420 include first and secondsutures 3412, 3422 and first and second flexible wires 3414, 3424. Thefirst and second flexible wires 3414, 3424 extend from the deliverydevice 3402 and each include a loop 3416, 3426 for receiving the firstand second sutures 3412, 3422 and for engaging a clasp (e.g., clasp 1200described above). Each of the first and second sutures 3412, 3422extends from the delivery device 3402, through a one of the first andsecond loops 3416, 3426, respectively, and back into the delivery device3402. In some embodiments, the first and second control members 3412,3422 extend through separate delivery devices 3402. The sutures 3412,3422 are removably attached to moveable arms of exemplary barbed claspsdescribed above. The first and second loops 3416, 3426 of the respectivewires 3414, 3424 are able to move along the corresponding sutures 3412,3422 such that the loops 3416, 3426 can engage the corresponding barbedclasps to engage the moveable arms. That is, the sutures 3412, 3422 areused to pull the moveable arms in an opening direction and the wires3414, 3424 are used to push the moveable arms in a closing direction.The wires 3414, 3424 can be made of, for example, steel alloy,nickel-titanium alloy, or any other metal or plastic material. Incertain embodiments, the wires 3414, 3424 can have a diameter betweenabout 0.10 mm and about 0.35 mm, between about 0.15 mm and about 0.30mm, and between about 0.20 mm and about 0.25 mm.

While various inventive aspects, concepts and features of thedisclosures may be described and illustrated herein as embodied incombination in the exemplary embodiments, these various aspects,concepts, and features may be used in many alternative embodiments,either individually or in various combinations and sub-combinationsthereof. Unless expressly excluded herein all such combinations andsub-combinations are intended to be within the scope of the presentapplication. Still further, while various alternative embodiments as tothe various aspects, concepts, and features of the disclosures—such asalternative materials, structures, configurations, methods, devices, andcomponents, alternatives as to form, fit, and function, and so on—may bedescribed herein, such descriptions are not intended to be a complete orexhaustive list of available alternative embodiments, whether presentlyknown or later developed. Those skilled in the art may readily adopt oneor more of the inventive aspects, concepts, or features into additionalembodiments and uses within the scope of the present application even ifsuch embodiments are not expressly disclosed herein.

Additionally, even though some features, concepts, or aspects of thedisclosures may be described herein as being a preferred arrangement ormethod, such description is not intended to suggest that such feature isrequired or necessary unless expressly so stated. Still further,exemplary or representative values and ranges may be included to assistin understanding the present application, however, such values andranges are not to be construed in a limiting sense and are intended tobe critical values or ranges only if so expressly stated.

Moreover, while various aspects, features and concepts may be expresslyidentified herein as being inventive or forming part of a disclosure,such identification is not intended to be exclusive, but rather theremay be inventive aspects, concepts, and features that are fullydescribed herein without being expressly identified as such or as partof a specific disclosure, the disclosures instead being set forth in theappended claims. Descriptions of exemplary methods or processes are notlimited to inclusion of all steps as being required in all cases, nor isthe order that the steps are presented to be construed as required ornecessary unless expressly so stated. The words used in the claims havetheir full ordinary meanings and are not limited in any way by thedescription of the embodiments in the specification.

What is claimed is:
 1. A clasp comprising: a fixed arm; a hoop-shapedmoveable arm extending from a first end to a second end and having abarbed portion; and a hinge portion hingeably connecting the fixed armto the moveable arm, the hinge portion comprising a plurality of springsegments, wherein each spring segment is connected to a plurality ofspring segments and the spring segments are arranged in a pattern havingthree columns and seven rows of spring segments.
 2. A clasp comprising:a fixed arm; a hoop-shaped moveable arm extending from a first end to asecond end and having a barbed portion; and a hinge portion hingeablyconnecting the fixed arm to the moveable arm; wherein the clasp isformed from a top layer and a bottom layer that are only joined in onelocation to allow the top and bottom layers to slide relative to oneanother during opening of the clasp; and wherein the top and bottomlayers are formed of shape memory material.
 3. A clasp comprising: afixed arm; a hoop-shaped moveable arm extending from a first end to asecond end and having a barbed portion; and a hinge portion hingeablyconnecting the fixed arm to the moveable arm; wherein the clasp isformed from shape memory material and the fixed and moveable arms areshape set in a preloading position so that a pinch force exists betweenthe fixed and moveable arms when the fixed arm is approximately parallelwith the moveable arm.
 4. A clasp comprising: a fixed arm; a hoop-shapedmoveable arm extending from a first end to a second end and having abarbed portion; and a hinge portion hingeably connecting the fixed armto the moveable arm; wherein the clasp is formed from shape memorymaterial and the fixed and moveable arms are shape set in a preloadingposition so that a pinch force exists between the fixed and moveablearms when the fixed arm is approximately parallel with the moveable arm;and wherein the fixed arm is bent in a closing direction beyond a closedposition to the preloading position.
 5. A clasp comprising: a fixed arm;a hoop-shaped moveable arm extending from a first end to a second endand having a barbed portion; and a hinge portion hingeably connectingthe fixed arm to the moveable arm, the hinge portion comprising aplurality of spring segments, wherein each spring segment is connectedto a plurality of spring segments; wherein the clasp is formed fromshape memory material and the fixed and moveable arms are shape set in apreloading position; and wherein the fixed arm is bent to at least about45 degrees beyond a closed position to the preloading position.
 6. Aclasp comprising: a fixed arm; a hoop-shaped moveable arm extending froma first end to a second end and having a barbed portion; and a hingeportion hingeably connecting the fixed arm to the moveable arm, thehinge portion comprising a plurality of spring segments, wherein eachspring segment is connected to a plurality of spring segments; whereinthe clasp is formed from shape memory material and the fixed andmoveable arms are shape set in a preloading position; and wherein aftershape setting, the fixed arm is prohibited from returning to thepreloading position by a cross-member.
 7. A clasp comprising: a fixedarm; a hoop-shaped moveable arm extending from a first end to a secondend and having a barbed portion; and a hinge portion hingeablyconnecting the fixed arm to the moveable arm; wherein a plastic limit ofthe material of the clasp is not exceeded when the moveable arm isopened to a fully open position about 140 degrees from the fixed arm. 8.A clasp comprising: a fixed arm; a hoop-shaped moveable arm extendingfrom a first end to a second end and having a barbed portion; and ahinge portion hingeably connecting the fixed arm to the moveable arm;wherein the clasp is formed from a shape memory material having a thickportion and a thin portion.
 9. A clasp comprising: a fixed arm; ahoop-shaped moveable arm extending from a first end to a second end andhaving a barbed portion; and a hinge portion hingeably connecting thefixed arm to the moveable arm; wherein the clasp is formed from a toplayer and a bottom layer that are each formed of shape memory material;and wherein barbs of the barbed portion are formed in the top and thebottom layers.